Rob Toonen

.... The other thread that I thought might be of interest to folks was the discussion that Ron Shimek and I have had with the same guy in regards to the nutritional value of the product Marine Snow ( http//www.reefs.org/ubb/Forum1/HTML/009753.html ) ....

Richard Harker

Rob

I've read a number of your comments on Marine Snow and have a couple of questions related to some of your statements.

You stated that particulate organic matter in your tanks runs 100-130 mg/l. Could you explain how you measured this and what you're actually measuring? How did you determine it is organic? Since most published studies that I'm familiar with give particulates in mg C/l, do you have an estimate for your tank that I can compare?

From your posts I take it that you think the typical reef tank has plenty of Marine Snow because you've written, ""Marine snow" is an aggregate of bacterial and particulate detritus that are agglutinated on/around a sticky molecule such as mucus." As you point out, a tank with corals is going to have plenty of mucus. Some time ago Ron Shimek wrote a column on plankton in his tanks and wrote, "All of the tanks showed a similar array of planktonic organisms. There were small microcrustaceans, mostly harpacticoid copepods and their larval and juvenile stages. I also found an occasional juvenile amphipod. There were numerous larval polychaetes (a.k.a "bristleworms"). These included several different developing embryos and planktonic larvae from at least two different families of worms, the spionids and the amphinomids. Interestingly enough, some of these larvae were quite large and advanced, indicating an age of more than a week, and all of them had food in their guts." In the studies I've done on my tank, I have found a similar array of organisms and I don't supplement the tank other than food for the fish.

Bob Stark is doing some very interesting work on bacteria in reef tanks. He's found that reef tanks have bacterial levels at least one and maybe even two magnitudes higher than the natural reefs I've measured.

We've got plenty of bacteria, we've got plenty of marine snot, we've got plenty of plankton, yet you argue that we should be dosing our tanks with phytoplankton (preferably fresh). Where's the evidence that tanks without supplemental phytoplankton are suffering? Your posts have made a great deal of your not wanting to use Marine Snow because you doubt it's value and effectiveness. What proof do we have that preserved phytoplankton is beneficial to a reef tank? You've been able to keep larvae alive with it, but how do you know that they would have died in a reef tank without supplemental feeding?

Rob Toonen

I've read a number of your comments on Marine Snow and have a couple of questions related to some of your statements.

I've just read your comments as well. I must say that I had no idea I aroused such animosity in you Richard -- there is no question about some of your statements. You seem to have a pretty liberal definition of a "direct quote" (I simply said that both debates were with "the same guy," and the phrase "that fellow" never appeared in any post I have made). Further, we have discussed the Spray-Dried Marine Phytoplankton issue in the past, and I'll explain one more time that my blending of ESV's SDMP is better than the average I have heard from hobbyists using the product -- it is a matter of a synergism between storage and blending rather than the mixing technique per se that causes a problem. I have discussed this with Bob Stark in detail, and suggested a change to the product directions as a result of my tests. In fact, I rather resent your oversimplified accusations, and particularly your derogatory comments about me and my motivations. Having gotten that off my chest, I won't continue to meet you in the mud, but will rather return to the discussion at hand.

You stated that particulate organic matter in your tanks runs 100-130 mg/l. Could you explain how you measured this and what you're actually measuring? How did you determine it is organic? Since most published studies that I'm familiar with give particulates in mg C/l, do you have an estimate for your tank that I can compare?

I explained how I measured it in the post to which you are referring -- this was a simple thumb-nail estimate. I did not do any biochemical analyses on the samples to determine the mg C/l, but rather did a gross estimate based on the weight of particulates remaining on a 0.2 um filter and checked for organic content via acid dichromate oxidation (granted this is not the most accurate quantitative test, but is only sensitive to organic carbon and provides a relative check for the weight measure). I'd be interested in seeing how these compare with your numbers if you have done any testing (gross estimates like mine, or the actual organic carbon content) on some reef tanks?

From your posts I take it that you think the typical reef tank has plenty of Marine Snow because you've written, ""Marine snow" is an aggregate of bacterial and particulate detritus that are agglutinated on/around a sticky molecule such as mucus." As you point out, a tank with corals is going to have plenty of mucus. Some time ago Ron Shimek wrote a column on plankton in his tanks and wrote, "All of the tanks showed a similar array of planktonic organisms. There were small microcrustaceans, mostly harpacticoid copepods and their larval and juvenile stages. I also found an occasional juvenile amphipod. There were numerous larval polychaetes (a.k.a "bristleworms"). These included several different developing embryos and planktonic larvae from at least two different families of worms, the spionids and the amphinomids. Interestingly enough, some of these larvae were quite large and advanced, indicating an age of more than a week, and all of them had food in their guts." In the studies I've done on my tank, I have found a similar array of organisms and I don't supplement the tank other than food for the fish.

Well, I'm reasonably certain that Ron, like me, feeds his tank pretty heavily, and it's not surprising to me that he found what he did. You, as an advocate of nonfeeding, ought to provide a control for us -- what is the particulate organic content of your tank? Do you have larvae in your bare tanks? What sorts, and do they have food in their guts? Again, though, the discussion will come down to that put to me -- is *your* tank considered typical of the method, and the answer must be "no." Every tank will be different, and everyone with a tank ends up with a personalized method of maintenance and methodology. I don't think that my tanks are all that different than the average, but I have no objective or quantifiable basis for comparison...

Bob Stark is doing some very interesting work on bacteria in reef tanks. He's found that reef tanks have bacterial levels at least one and maybe even two magnitudes higher than the natural reefs I've measured. ,

That what he was telling me. I am looking forward to seeing his results, and the new test. It could well be that the particulate matter isolated from my tank is largely or entirely bacterial, but I didn't really examine the particles beyond what I have described...

We've got plenty of bacteria, we've got plenty of marine snot, we've got plenty of plankton, yet you argue that we should be dosing our tanks with phytoplankton (preferably fresh). Where's the evidence that tanks without supplemental phytoplankton are suffering?

Well, the trend to develop tanks around deep sandbeds with consistent feeding seems to be spreading, and concurrently, there seems to a dramatic increase in reports of animals reproducing in people's reef tanks, and the observed biodiversity in an average reef tank (if the number of questions for ID of some obscure invertebrate group that Ron and I field on the net these days are any indication). I would say that provides anecdotal evidence for the benefit of feeding phytoplankton to reefs tanks. Other examples include reports such as that from a clam distributor in SoCal who discovered mortality in juvenile clams dropped from roughly 10% of the clams in each batch, to just about 1% after supplementing phytoplankton regularly.

Your posts have made a great deal of your not wanting to use Marine Snow because you doubt it's value and effectiveness. What proof do we have that preserved phytoplankton is beneficial to a reef tank? You've been able to keep larvae alive with it, but how do you know that they would have died in a reef tank without supplemental feeding?

There are plenty of animals found on reefs that specialize on particles the size of phytoplankton, and there are plenty of studies in both the aquaculture and larval biology literature showing that phytoplankton provide specific nutrients lacking in traditional food products. It is of course impossible to follow a given larva under both conditions and show that one would survive while the other would fail, but it is possible to determine whether or not a given product is capable of supporting the growth and survival of some of the animals in question.

To summarize my position in the original thread to which I provided the link, my feeling on the TLF product is that Marine Snow will likely feed something in the average reef tank (especially those with a live sandbed) but whether it provides as nutritious a food source as a mixture of the individual components each stored and dosed separately, I think is open to vigorous debate! If there is nothing else available to you, I'm sure it's a big step up on traditional 'liquid invertebrate foods' (based on pea flour and yeast), but if you can get and dose the various components individually (e.g., see my list and the links above), I think that you'll be better off doing just that.

The primary argument I have seen in response to that is that we should not use the survival of larvae as a surrogate for the feeding of corals and other invertebrates in reef tanks. My response to that is simply that larvae *are* corals and other invertebrates. Developing an artificial dichotomy like this makes it sound as if "larvae" are somehow a different critter than what we're keeping rather than just a baby of the same animals. The larvae I used are exactly the type of animals people try to keep in their tanks nudibranchs, snails & feather-duster worms. These are some of the animals that these products claim *explicitly* to feed, so it seems a reasonable thing to use in such feeding trials to me. Furthermore, most aquarists are thrilled when their animals reproduce, and are not only interested in feeding the adults, but also the larvae of the species in their care. As feeding and more realistic habitat recreation become more common, we are seeing more and more reports of animals reproducing in people's reef tanks, and the reported biodiversity is constantly increasing (as I mentioned above).

In my opinion, there are a number of good reasons to use larvae as a test subject for such feeding studies

1. they are small and grow quickly, so an accurate assay can be done over the period of about a month on thousands of individuals to get a mean growth and mortality response and an estimate of the variation in response among them. That is certainly not true of adult colonies of corals, and the amount of work it takes to do the feeding trials I have already done would be nothing compared to the amount of time, space and effort it would take to use the adults.
2. It is a simple system in which other factors such as lighting, filtration and such between tanks can be controlled. Obviously the more uncontrolled factors that enter into an experiment, the more difficult it is to draw any conclusions about the results obtained from it.
3. Larvae are generally more sensitive than adults and the effects of malnutrition or toxicity are much more easily detected than among adults.

Some will undoubtedly argue that the use of larvae makes the test too conservative, and that some extra nutrition to corals is better than none at all. I would have to say that I agree with the latter but not the former. It is certainly more conservative to use larvae, but I also used filtered seawater controls in which the larvae survived longer than those fed on the room temp preserved phytoplankton. To me, the only reasonable interpretation of that result is not starvation or malnutrition -- it is detrimental to the survival of the larvae. I like the fact that my animals are reproducing, and that the supplemental feedings I provide seem adequate to support both the adults and the larvae of animals in my aquarium (BTW - it is standard ecological practice to use larvae for bioassays in this way, and the rationale is well-described in the primary literature in addition to my reasons here). My personal feeling on the subject is, therefore, I don't want to add anything to my aquarium that, in isolation, is found to be detrimental to the survival of those animals, and that includes preserved phytoplankton stored at room temperature. In any case, my own feeling is that until someone undertakes the next step of designing and executing the grand experiment on adults, I am personally willing to be a little conservative when it comes to spending my money on anything to add to my tanks...

I have asked Julian to participate in the discussion, and cc'ed him my Email in the hopes that he'll join us. In any case, I hope that clears things up a little for you.

Richard Harker

I've just read your comments as well. I must say that I had no idea I aroused such animosity in you Richard <snip> In fact, I rather resent your oversimplified accusations, and particularly your derogatory comments about me and my motivations.

It is not a matter of animosity and I don't consider the comments derogatory (well maybe the line about PhDs). It is a matter of expecting intellectual honesty in these discussions. On the basis of your lavae test some months ago you declared ESV's dried phytoplankton worthless. Your words were quite strong on the subject. After you had made numerous critical posts on the subject, your learned that a scientific study had found that spray dried phytoplankton was more effective than all but live phytoplankton and you also learned that the spray dried product has to be blended to reduce "clumps," something you apparently didn't do adequately when you tested the product.

Inspite of learning these things, you've made no effort to correct your statements except when confronted with these facts in our exchanges. To the best of my knowledge you've never really rescinded your conclusions about ESV. You've just danced around the issue. As of a few weeks ago you still referred people to the archives where your misstatements are found. In my mind that adds up to intellectual dishonesty. The least you should do is make as much effort to correct your statements as you made when you first made them. I have yet to see you acknowledge in any discussion that you're now aware of research that shows spray-dried phytoplankton to be effective. Your efforts seem more directed at selling algae paste than objectively looking at the alternatives.

There are plenty of on-line advocates that tout one thing or another. In general, the advocates are just hobbyists who have good luck with something and want to share their experience with others. However, when one portrays himself as an expert or trained professional and using that authority touts a product or method, then the issue no longer balances between hobbyists with different experiences, it balances on the expertise of the touter. That opens the person to criticism that one might take personally and consider animosity. It is neither.

I'd be interested in seeing how these compare with your numbers if you have done any testing (gross estimates like mine, or the actual organic carbon content) on some reef tanks?

I'll shortly have some carbon figures to compare to the bacteria figures. I may present the results at MACNA depending on time constraints.

Do you have larvae in your bare tanks? What sorts, and do they have food in their guts?

Yes. I periodically qualitatively check both the sand and the water column. My observations mirror Ron's Reef Tank Plankton article observations. Since neither Ron nor you have provided quantitative estimates of laval numbers, I don't see what we can compare.

Every tank will be different, and everyone with a tank ends up with a personalized method of maintenance and methodology.

This is where we alway end. We hear at length about how we need a deep sand bed because otherwise we won't have the proper chemical processes going on and we won't have the mix of sand dwelling organisms that we need. Then when questioned, the response is, "well, every tank is different." We hear about how tanks cannot grow larvae without supplemental (preferably live) phytoplankton and then when questions are raised the response is, "well every tank is different." Well of course every tank is different and to make sweeping statements like we need to feed reef tanks phytoplankton to maintain larvae is clearly something that can't be substatiated.

Well, the trend to develop tanks around deep sandbeds with consistent feeding seems to be spreading, and concurrently, there seems to a dramatic increase in reports of animals reproducing in people's reef tanks, and the observed biodiversity in an average reef tank I would say that provides anecdotal evidence for the benefit of feeding phytoplankton to reefs tanks.

I would hope that you would fail one of your students who used such logic to prove cause and effect. Even if you're right about increased reproduction (and I question that) there are all sorts of possible explanations. Are you suggesting that unfed tanks are not reproducing?

Other examples include reports such as that from a clam distributor in SoCal who discovered mortality in juvenile clams dropped from roughly 10% of the clams in each batch, to just about 1% after supplementing phytoplankton regularly.

We know that it is very difficult for small clams to meet their metabolic needs from sunlight alone. Considering how dimly lighted most wholesalers tanks are, I'm not surprised. So we have one juvenile organism that we can argue needs phytoplankton. On the basis of that, we can conclude that all tanks need phytoplankton?

There are plenty of animals found on reefs that specialize on particles the size of phytoplankton, and there are plenty of studies in both the aquaculture and larval biology literature showing that phytoplankton provide specific nutrients lacking in traditional food products.

I'm not sure what you mean by "traditional" food products. Are you talking about yeast based products? I didn't know anyone still used those old supplements. In any case, the fact that there are animals that feed on particles the size phytoplankton is not sufficient reason to dose a tank when it is quite possible that those same sized particles can be produced by the tank at less risk to it.

I thought the point of "natural" reef tanks was to recreate as many natural coral reef processes in the tank as possible. Wasn't that your argument for deep sand beds? Now you've reversed course and said that we can't produce phytoplankton in the tank so we now have to add "food grade preservatives" to the tank. How natural are "food grade preservatives"? How does that fit in with your vision of a complete functioning ecosystem in a glass box? Given your concern for putting additives in the tank, I also wonder why you would rather add food grade preservatives to the tank rather than spray-dried phytoplankton that has no preservatives.

Rob Toonen

My reason for directing people to those threads in the first place was that I had not spent a lot of time on the list of late because of the time invested in those discussions, and I thought that people here were likely interested in the topics as well.

I missed the original postings so if you want to include the URLs your talking about that would help.

The original discussions were taking place on at http//www.reefs.org/ubb/Forum1/HTML/009753.html for those that are interested and missed it. The answers to my recommendations on feeding choices (should you want to feed your tank) are below. I apologize to those interested in that information that you have to read through the banter between Richard and I to get there, but it is in here...

Well, Richard, I can honestly say that you never fail to amaze me, and this post was a prime example... I used to think people were over-reacting to you when they left various boards over debates like this. I just assumed that you had appointed yourself Devil's Advocate for the reef hobby and were trying to explore the reasoning behind things, and that you were simply misunderstood, but more and more I'm starting to agree with one of the former list members who told me "arguing with Harker is like beating your head against a brick wall -- it never accomplishes anything, and it feels *so* good when you stop." This thread has already gotten much more personal (and therefore lacking in objectivity) than I would like (or usually participate in), but to be blunt, you have pissed me off and I can't ignore this.

It is not a matter of animosity and I don't consider the comments derogatory (well maybe the line about PhDs).

Perhaps derogatory means something different in your native tongue, but in mine, the entire thread could be considered so. In fact, I was pointed to the thread by 3 different sources who asked if I had

1. slept with your wife,
2. seduced your daughter, or
3. spit in your food at MACNA

I would interpret that as suggestion that others felt the same way... It seems that you never fail to twist the knife whenever the opportunity presents itself, and I just don't see any reason for that.

It is a matter of expecting intellectual honesty in these discussions. On the basis of your lavae test some months ago you declared ESV's dried phytoplankton worthless. Your words were quite strong on the subject. After you had made numerous critical posts on the subject, your learned that a scientific study had found that spray dried phytoplankton was more effective than all but live phytoplankton and you also learned that the spray dried product has to be blended to reduce "clumps," something you apparently didn't do adequately when you tested the product.

Golly-gee, here we go again. We've already been through all of this right here, Richard. Let's try this again -- the post (it's at http//www.reefs.org/library/article/r_toonen15.html for those of you who have missed it) starts with a discussion of SDMP that states "The spray-dried product has some advantages (primarily cost and storage) and some disadvantages (primarily size and nutritional composition) over live or cryo-preserved phytoplankton. It depends on which animals you're feeding which product will best suit your goals." The remainder of that particular post is directed primarily at the use of Spirulina as a phytoplankton food (as opposed to ESV's product), and in our discussion last time I explained that the information contained in that post is all still valid. I'm not going to divulge any trade secrets here, but you know as well as I do that SDMP is not exactly "phytoplankton" -- my original criticisms of the product were that

1. the particle size is outside the range that we were discussing as phytoplankton, and
2. despite repeated requests for information from the folks at ESV, we knew nothing about the nutritional profile of the food.

There are known problems with the drying of kelps for food products, and given that concern along with the lack of information from the supplier and the poor performance of the product in my feeding trials suggested that it was not a great phytoplankton supplement. That was not my original post on the subject, but rather a follow-up in the discussion in which someone suggested Spirulina might be a better alternative. My original post (which I cc'ed to Bob Stark) did not have as much detail, however, and simply made these points and ended that until the nutritional information was released by the company, there were several reasons to be suspicious of the utility of such a food product.

The "scientific" study to which you refer is an anecdotal description of a shrimp farm that has decreased mortality in the larval shrimp as a result of partially switching from total live algae to the parent product of the SDMP. There are no controls, there is no experiment, there is no "science" involved. There is only "data" from this great study to which you refer is the statement that survival for the culture shrimp P. monodon larval survival increased to 42% using it "at 70 percent replacement level," compared with 23 percent survival using "traditional feeds." Traditional feeds remains undefined, and as an unreplicated and uncontrolled study, I hardly consider it "scientific." Later studies by CIAD in Mexico are better, but find that the food performs *almost* as well as live phytoplankton ONLY after the initial stages of larval development (Z1) are fed on live phytoplankton (for which the product failed to perform, similar to the results of my testing) -- after the first zooeal (larval) stage, however, there is no significant difference in the survival rate or development time to post-larval stage among larvae fed on live phytoplankton and the SDMP product, although the animals grown on live phytoplankton were significantly *larger* than siblings raised on SDMP. It is also worth noting that the larvae become more omnivorous during this period, and will gladly accept rotifers and newly hatched brine as well as phytoplankton.

The nutritional profile has now finally been released, and although completely lacking in EPA, the product has a pretty good profile, with one of the highest concentrations of any product out there for DHA. Together with my tests, these results can be easily interpreted as an issue of particle size, and the fact that advanced stage shrimp larvae do perfectly well on the food is not surprising given the particle size obtained by mixing this product. Contrary to your claims that my ignorance in the proper method of mixing the product was the cause of my failed tests (FWIW, the instructions for mixing the product were never provided BTW), the dried product clumps irreversibly during storage, and even the parent company has completely backed down on their original particle size distribution claims and now prints "particle sizes in the range of 10-80 microns."

In fact, after I completed my tests I sent Bob this Email

Bob,

Bhat new bottle that you sent me turned out to be quite informative, and I started running some tests to see what effect storage duration and mixing technique had on the mean particle size generated from the product.

Mixing method

Storage condition & duration

I thought you might like to have these data, and it may be worth passing along to your customers that both the storage (I would be inclined to recommend storage in a freezer for long-term) and mixing method make a substantial difference to the mean particle size being offered to the animals.

Rob

Your implication that I was too stupid to follow the directions and mix it properly are perhaps the most insulting of the long list of your derogatory accusations in these discussions...

Inspite of learning these things, you've made no effort to correct your statements except when confronted with these facts in our exchanges. To the best of my knowledge you've never really rescinded your conclusions about ESV. You've just danced around the issue. As of a few weeks ago you still referred people to the archives where your misstatements are found. In my mind that adds up to intellectual dishonesty.

Well, no I have never rescinded my conclusions about ESV because there were largely correct "the product has some advantages (primarily cost and storage) and some disadvantages (primarily size and nutritional composition) over live or cryo-preserved phytoplankton." You might want to re-read that original post again Richard, because your claims about what I said are quite different from what I wrote. I don't actually recall directing anyone to that particular article in the #reefs archive, but if you are referring to the archive itself rather than that particular entry, then you are absolutely correct, and I will continue to do so. There is a *lot* of good information there, and I will continue to direct people to the #reefs library for that reason ( http//www.reefs.org/library/index.html for those of you who have not yet found this).

That I have made no effort to clarify my comments in regards to SDMP, however, is simply false, and I had sent a revised version of that post to the administrators of at the end of February -- granted I had assumed that it had been changed without checking, but I can't say that I go back to read those things very often, so I didn't realize that it had not been updated. I have sent an email to the folks there to find out what happened, though. I also cc'ed all my original posts on the subject to ESVCo, but Bob apparently missed the original posts and he and I have discussed this at length (both on the phone and via email) subsequently.

Well, here we go with the knife twisting again -- I can't remain as civil as I would like with this, and would have to say that you're about as liberal with the collection of second-hand information as you are with the application of quotation marks (which is generally pretty black-and-white on the subject of intellectual dishonesty, BTW). You've already appointed yourself the judge, jury and executioner in my case (despite the fact that we've had this discussion twice now), so what difference does it make whether or not we have the discussion again? You've obviously taken away what you wished to hear from our previous discussion on this subject rather than what I am saying, so it seems rather pointless to continue the discussion in the hopes that you'll listen this time, but I can't let this pass without comment...

The least you should do is make as much effort to correct your statements as you made when you first made them. I have yet to see you acknowledge in any discussion that you're now aware of research that shows spray-dried phytoplankton to be effective. Your efforts seem more directed at selling algae paste than objectively looking at the alternatives.

I'd say that is bordering on slanderous -- I have no stakes in any of these products, I don't make any money from this, and (even assuming that your long-term association with Stark has nothing to do with this little vendetta of yours) the same could be said about your post and the SDMP. I *have* made those statements. I *have* acknowledged that "research" in which you put so much faith (it is ironic to me that you hold this study in such high regard when dismissing actual controlled research which disagrees with your premises in other debates). I *have* recommended the product, and frankly I resent your implications that I am somehow selling something. I am participating in this as a hobby, and, unlike some, I do not make a living at doing it. What exactly could be my motivation for "selling algae paste [rather] than objectively looking at the alternatives?"

For my part, I simply want to find out what's best for my tank, and I share my results with others (too freely according to you, if I remember correctly). You're not going to try to tell me that you never offer your opinion on any products available for the reef hobby are you?

There are plenty of on-line advocates that tout one thing or another. In general, the advocates are just hobbyists who have good luck with something and want to share their experience with others. However, when one portrays himself as an expert or trained professional and using that authority touts a product or method, then the issue no longer balances between hobbyists with different experiences, it balances on the expertise of the touter. That opens the person to criticism that one might take personally and consider animosity. It is neither.

It is if the basis of that criticism is fallacious, and based on the misinterpretations and/or misquotations of the person doing the criticism. I've just been through this with Randy in the threads on which I originally posted -- what, do they require you guys to fail a reading comprehension test before you're allowed to join your little private list? I must say that I'm getting ever more annoyed with your insinuations here, Richard.

Here is a post of mine from the Aqualink archives in response to a request for information that should answer the questions of (I've added in the links and changed the text to make sense where I simply had a link previously)

The basic ingredients of Marine Snow are being determined by Ron Shimek right now, and he will be presenting a comparison of all the liquid invertebrate foods at MACNA that will be written up and submitted after that. I'm sure that will be a more detailed and thorough discussion of what's in which products, but I can give you a thumbnail sketch of them. The most attractive products are those that contain phytoplankton, because these tiny floating algae are one of the key sources of nutrition for a lot of reef-dwelling animals, and are all but completely lacking from our tanks. You can read a little more about the benefits of phytoplankton and why it should be added to a reef tank in this product information sheet I wrote for DT's Phytoplankton ( http//st6.yahoo.com/lib/worldwidepet/plankton.htm ). The products such as Kent's Phytoplex and Sprung's Marine Snow contain dead, preserved phytoplankton, and their advertising claims that they provide a nutritious food source for marine suspension feeders (such as soft corals, clams, feather dusters and the like). My argument is that until they produce some data to support that claim, my tests with preserved phytoplankton stored at room temperature suggests that it is anything but nutritious (see below), and we ought to continue to support products that have passed such feeding tests with flying colors.

In general, if you ask me what I would consider a suitable product for feeding the suspension feeding animals in a reef tank, I would suggest a combination of some zooplankton (or surrogate) and some phytoplankton to cover the range of size particles on which most reef animals seem to specialize. For the small "zooplankton" size range, live rotifers -- available from suppliers like Mountain Corals ( http//www.mountaincorals.com/rotifers.htm ), Inland Seafarms ( http//www.rotifer.com/zooplankton.htm -- which will also provide live copepods and mysids soon for more variety), or Liquid Life ( http//sites.netscape.net/liquidlifeusa/index.html ). For artificial surrogates of roughly the same size range, ESV's spray-dried marine plankton (SDMP -- I'll come back to this below), BrineShrimpDirect's Golden Pearls ( http//brineshrimpdirect.com/product.htm#gold-pearls ), or A.P.R. (Artificial Plankton Rotifer) should probably perform nicely.

In terms of phytoplankton, there are no really good substitutes for the real thing. If you get SDMP fresh from ESV, store it in the freezer, and actually use a blender to mix it for 2 minutes like the directions suggest, you do get a lot of particles in the correct size range. If you get it from the petshop, store it on the shelf behind the aquarium (like I did during my tests) and then (even worse) mix it by hand (as most people do!), then the particles come out at roughly the size of rotifers rather than phytoplankton. The best source of phytoplankton for a reef tank remains live cultures, which are available from suppliers such as DT's Marine Phytoplankton Farms & Liquid Life USA.

My tests with marine phytoplankton suggest that even live product stored at room temperature for more than about a week resulted in a significant decline in the growth rate of the larvae to which it was fed, and some of the bottled phytoplankton products resulted in the death of larvae to which they were fed at a rate faster than starvation in filtered seawater. I did not test any phytoplankton product stored at room temperature that performed anywhere near as well as the live (to be fair, though, there are more coming out all the time and I can't keep up with them all -- someone may yet figure out how to preserve the nutritional value of phytoplankton at room temperature, but I'll wait for the test results before I'll be adding it to my own tanks ;) ). The only preserved dead phytoplankton that I tested which performed equivalently to live was the cryopreserved Instant Algae Paste from Reed Mariculture. This appears to last about 6 months in the average freezer without any appreciable degradation (on the other hand it is easy to over feed). You should also only plan on buying only as much as you can reasonably use in about that time, because there was a significant decrease in the performance of the paste somewhere in the 8 month range... You can read a lot more about phytoplankton, how to feed it and such in the phytoplankton archives if you're interested...

Rob

This is where we alway end. We hear at length about how we need a deep sand bed because otherwise we won't have the proper chemical processes going on and we won't have the mix of sand dwelling organisms that we need. Then when questioned, the response is, "well, every tank is different." We hear about how tanks cannot grow larvae without supplemental (preferably live) phytoplankton and then when questions are raised the response is, "well every tank is different." Well of course every tank is different and to make sweeping statements like we need to feed reef tanks phytoplankton to maintain larvae is clearly something that can't be substatiated.

Where in any of my posts or writings do you see me say anything to the effect of people "need" something to be successful at reef keeping? I have posted and written *many* times that there are no absolutes in this hobby, and that there are as many "correct" ways to keep a reef tank as there are people with a nice reef. The only place that I ever see or hear a claim that hobbyists "need a deep sand bed" or the like is when people like you criticize the information that Ron and I have posted on the subject. I would have to say that perhaps my most frequent quote in such posts would be something to the effect of "I have often said that there are no absolutes in any biological undertaking such as a reef tank, and that it is up to the individual in each case to learn what is involved and make an informed decision for themselves what is best for *their own* tank." The fact of the matter is that every reef tank is different, no matter how much that upsets reductionists that want to develop a recipe for keeping a reef tank based on a number of simple parameters. I just explained this in the original debate on Reefs.Org

"I think that the basis of our disagreement here stems from the fact that we have different philosophies of aquarium keeping. My experience is that chemists, in general, tend to be reductionists who view tanks as a carefully balanced set of equilibrium equations that require constant monitoring and modification to maintain, hence the attention to the exact levels of every parameter in the tank. Biologists, on the other hand, tend to come at the system from the other side, and view it as a complex whole which tends to thrive best with a bit of benign neglect, and tend to rely on the animals to determine the conditions of the system, hence the reason that they often have to purchase test kits to determine the actual levels of any given chemical constituent in the aquarium. I can't say that either way is better than the other, and I have seen beautiful tanks maintained with each philosophy, but it does tend to lead to some friction when discussing the relevance and importance of any given factor to the well-being of a reef aquarium."

The reductionist approach is obviously attractive, because it reduces reef-keeping to following a set recipe and simply tweaking parameters to match those measured and outlined by an authority figure -- the animals in the tank, if considered at all, are peripheral to the ultimate design and maintenance of the tank. The flip-side requires much more effort on the part of the aquarists to learn the biology of the critters and develop a reasonable facsimile of the habitat from which they originally derive, and that appears to be a less attractive path to some at the outset. I'm not convinced either way is right or wrong, just different, and I happen to favor the opposite approach to yours...

I can tell that this is headed south already, and there are far too many personal digs in this exchange for my tastes. Hopefully we can turn it around to some sort of useful discussion before it degrades completely.

Richard Harker

Book-length posts are painful to endure, so I will spare anyone following this thread any lengthy quotes and long responses (well, maybe not entirely). You're suggesting that I've misquoted you, but all I did is cut and paste your comments. I changed nothing of what I quoted. I suggest that you review what you originally wrote.

More than half of your reply is about me personally. You've used words like "perhaps derogatory means something different in your native tongue" and "It seems that you never fail to twist the knife whenever the opportunity presents itself" and my favorite "your implication that I was too stupid to follow the directions and mix it properly are perhaps the most insulting of the long list of your derogatory accusations in these discussions..." These reactions, especially the one about my being libelous really seem to be an over-reaction. Take that last comment about your being too stupid. This is what I actually wrote "It turned out that he had not blended the ESV properly, it had clumped together, and the clumps were too big to be consumed." That is factually accurate. Yes, ESV ought to take some, maybe even all, of the blame for not emphasizing that on the directions, but the fact remains that it was quite possibly the size of the particles and not inaedquate nutritional value that caused the larve to die. That's significant but you haven't really addressed that in follow up comments. Did you mention it at WMC?

I note that you've directed interested people to a reefs.org message that has nothing of your direct comments about ESV. Why don't you direct people to the post where you gave your conclusions and recommendations based on the larvae tests? If people look at those they will find that comparing frozen phytoplankton, DT's, and ESV you said that the larvae fed the ESV died and that you couldn't recommend it.

Most people don't like to add anything to their tank that kills things, so when you use words like that, the words tend to carry a great deal of weight. Now there's reason to believe that prepared differently, the ESV may have supported the larvae. You don't know because you apparently haven't repeated the test. Under those circumstances, softening your criticisms regarding ESV would seem to be the fair thing to do. You haven't done that. (And just for the record, I have no financial interest in ESV, don't even know Bob that well except from Fishnet, and while I use ESV products, I pay for them like everybody else.)

This post has already gotten too long. I suggest you review the comments you made when you came out against the use the use of ESV and see if in retrospect they were maybe a little overstated. I also suggest that you reread my quotes of your comments so that you can confirm their accuracy. Then check out the message "baby food for reef tanks?".