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Members' Aquariums Series - Eric Borneman

'My L'il Ol' 40 Breeder', Presented December 8th, 1998 on #reefs IRC.

I feel a little strange talking about my "unskimmed" tank, since all of my tanks are unskimmed and for some time now. However, I thought a description of my first, my original, and my oldest - and my favorite - would be both approachable and informative for most.

My main tank system is a 320 gallon reef which overflows into a 75 gallon seagrass planted tank with patch reef community which then overflows into an intertidal sump to a refugium, to a surge. Clearly, this is not something the average person can have - space or expense-wise. But, there are a lot of features of this system that are pretty nifty and could be incorporated into other simpler designs. Still, I chose the more romantic story of my 40 gallon Jaubert-style tank. The story is as follows:

In March of 1994, my three year old companion, a spotted watchman goby (Amblygobius guttata) was swimming normally in my (then) 75 gallon reef tank. All was well, nothing new or unusual, and no dangerous neighbors. We went to sleep, and I was put in a panic the next morning by a voice calling for me urgently - something about "Oh my GOD! What happened to our goby??!!" Well, somehow, something, some way had bitten or removed his entire tail past the anus. Gone. The poor guy was alive, not bleeding, but having a terrible time staying submerged.

I hospitalized him, treated him, and he miraculously recovered. The dorsal fin lengthened to meet the caudal fin around back with a small opening where his intestine met the outside. He regained most of his ability to swim, but was forever finding his rear end floating toward the surface. Clearly he couldn't compete well in the 75, so I decided to set up a small 20 gallon tank for him alone. I had been reading about the "Jaubert" tanks of Monaco, and had been using live sand for awhile in other tanks - with a plenum. I set up this tank, again using live sand and a plenum (I used 100% live sand at that time - when it was actually good quality) and added some live rock from my main tank's sump. I figured the bioload was destined to be very low, and opted to try this tank without a skimmer. The goby found his new home acceptable, and I was resolved to do lots of water changes, if necessary.

Things went well for several months, and I decided to add a few coral fragments here and there. Things still went well, so I started stocking the tank a little more and more. I was diligent every morning with my kalkwasser and additions (at that time) and I fed sparingly. As the tank became more "reef-like," I found myself waking every morning in a cold sweat, prepared to see disaster. A crash, an algae bloom, death, something!!! But, it never happened, and the tank ran really well.


Over the months, I got several orders of livestock and occasionally had a sick coral or a sick fish. To isolate them, I sometimes put them in the 20 gallon, and they frequently recovered - and also seemed more "relaxed." I realize this is not exactly the stuff of science, but it was quite perceptible. In time, I started calling this my "healing tank," because things seemed to recover easily in here, albeit I didn't know why.

All the water parameters stayed rock solid and of very high quality. I eventually stopped sweating quite so much at night, and gained a little confidence. I started feeding more heavily. The system responded without a hitch, and concomitantly more particulate matter appeared. I reasoned that the time food and additives stayed in the water without being skimmed out was certainly a good thing, but questioned its ultimate limits and abilities. In other words, so far, so good, but when would it end? Everything was growing well, and I started seeing good sponge growth - kind of novel compared to the big ol' skimmer tank. I liked what I saw, so when the LFS had a sale on a 40 gallon breeder in June of '95, I bought it. I also bought a 120 gallon tank as things were outgrowing the 75 I mention this because now is where it got very intriguing for me.

First, I dismantled the 75 and set up the new 120. When I moved the sand over, I simply scooped it out and placed in on the bottom of the 120 - no plenum this time. The sand had detritus, but it was more or less, just sand with some polychaetes and spaghetti worms in it - nothing remarkable. And so it was done.

Then, when I went to set up the 40, I dug down in the sand of the 20. This sand in this tank was noticeably stratified with algal mats below the surface, some black areas, and was chock full of life. BUT, at the was warm! Noticeably warmer than the upper levels - and it felt warm to me which meant probably warmer than my body temperature? Like a compost pile.


I transferred everything over, added more sand, and again used a plenum. I did things very methodically because this was becoming my favorite tank. I made a trip to Pensacola and got some plankton. I added as much diversity in odd stuff like algae and snails and what we now call "detritovores" as I could - I added more corals and a few more fish. The goby was giving me a two fins-up sign, so I figured I was doing ok.

And I fed.
And things grew.
And grew.

And water quality was better than in the 120 with the big skimmer. And I puzzled and puzzled till my puzzler was sore. Of course, I got geeky and started reading about sediments at this time, and over the next year, started doing some culturing. I fed live foods. I stopped adding iodine and strontium. I fed the sand directly with sinking pellets and flake food.

I really started to learn the system and was totally impressed.- still too scared to drop the skimmer off the 120, but I did convert my 10 gallon quarantine and set up another tank without a skimmer. I was in a smaller house then, and people started to wonder a little, I think - too many tanks, too many books, getting geeky. More followed, too - sigh!

When I moved to Houston, I carefully moved the forty by draining the water down to the sand, babying the rock with corals (all attached by now and looking very "reefy"), and left the sand intact - it was still very heavy!!! I carefully replaced everything as it was on my arrival and things continued as normal. However, the trip took its toll on several Acropora from this tank, and I lost the goby - very sad day!! I buried him under a tree in my backyard. The trip also took a heavy toll on other tank stuff, but that¹s another story. Now, over the past two years, things have been stable and really rocking - no screwy house wiring, no bad water problems, etc.

I pulled the skimmer off the 120 (again with plenum), and set up several more tanks. I have had one very bad happening that occurred while I was out of town - about ten months ago. I had a near total wipe out of the coral from a negligent kalkwasser addition in my absence, as best as I can figure - still not positive that my "maintainer" told the whole truth about events. But, in the past ten months, the tank has recovered totally and has even surpassed its former glory, sans a few lovely corals. It reacted like a hurricane event - like the freed substrate and die-back was merely a "refresher."

So, having now set up and maintained well over a dozen personal unskimmed tanks, as well as helping countless others with their own systems, I'm sold. I'm going to spend a few minutes now, trying to offer some tidbits of hat I have learned, and what I see as strengths and weaknesses of these style tanks. In addition, there are several aspects I need to consider for the future of this and all my tanks. I'll also describe the tank and its set-up as it currently stands.

tank size:
40 gallon, breeder
4-6" mixed grade aragonite sands, 1.5" plenum
live rock:
Fiji - very little - maybe 25 pounds total?
1 x 175 watt 10000K Hamilton,
2 x 95 watt VHO Hamilton actinic
water movement:
3 x 195 gph powerheads
other equipment:
4 + years
Kalkwasser, approximately 1.5 gallons/day
water changes:
5 gallons every two weeks - NOT required for nutrient export
twice per day and once at night.
multiple types of fresh carnivore/herbivore and vitamin mix,
homemade, multiple live algae cultures, rotifers, live Artemia
nauplii, plankton when available
Current livestock: (always changing, and impossible to ever list it all)
* captive bred, indigenous, tank raised, or tank reproduced
Pseudocheilinus hexataenia
Amblygobius guttata
Psuedochromis sankeyi*
Synchiropus picturatus
Alpheus sp.
juv. Heteractis aurora?*
Opheothrix sp.*
Opheolepis sp.
various other brittle stars, Bioluminescent stars
Trochus, Nerites , Stomatella , Lima, Astraea spp.
(3) Montipora sp. morphs* - very dominant, forming microatolls at the surface, and almost lending a monospecific tangle to the entire water volume.
Astreopora sp.
Echinophyllia sp.
(2) Protopalythoa sp.*
(4) Acropora sp.*
(3) Porites sp.*
(3) Palythoa sp.*
(2) Favia sp.
(2) Zoanthus sp.*
Xenia sp.*
Favites sp.
Hydnophora sp.*
Pocillopora sp.*
(3) Pavona sp.*
Stylophora sp.*
Fungia sp.*
Parazoanthus sp.*
Pectinia sp.
Seriatopora sp.*
Goniopora sp.*
Oculina sp.*
Halimeda sp. *
Dictyota sp.*
Gelidium sp.*
Ochtodes sp.*
Graciliaria sp.*
approximately fifteen unknown species*
a whole world of attached, benthic, and pelagic flora and fauna hopefully soon to be identified.

What I did Right, and What I did Wrong.

One of the best things I did with this particular system is that I "went slow." Granted, this is good advice irrespective of situation, but in this case, I think it makes even more of a difference. Sure, my original patience was based mostly on a sense of impending doom and curbed panic, but it was a happy accident. Quite fortuitous.

I have learned over this time that a plenum is mostly one of principal rather than practice. Its interesting in concept and theory, but seems fairly useless. I have learned that deeper sand beds work better than shallow ones. I have learned that corals can be substantial water column purifiers - and that biodiversity is both beneficial and a natural consequence of these tanks.

Particulate matter and food is infinitely more available as a food source. Sand beds should not be disturbed as I thwarted two near disasters after major sand stirring. Natural cycles of both algae and plankton occur - much more typical of nature than traditional tanks.

One cannot act rashly with unskimmed tanks, yet they are very resilient and forgiving. The amount of food that is able to be processed by even such a small simple system is formidable. Water clarity and nutrient levels remain excellent.

Water movement, especially without a sump for water to fall into, is perhaps even more important than in tanks employing skimmers. Biofilms play a more naturally important role here. In general, these systems look and act much more like a natural reef.

What have I learned, what mistakes were made? Thankfully very few. One inherent weakness of this tank is the small actual water volume - there probably aren't but fifteen gallons of water in the whole tank once you take out the rock, sand, and corals. I would be happier with a 400 watt metal halide rather than the 175 currently installed.

Observation is key, because there is no "safety net" if things go wrong. Thankfully, things don't wrong much as the system is very stable - it really takes a lot to throw them off. I would not use a plenum again, opting for the additional sand as it would be more beneficial. I would like to have a refugium present, but space doesn't allow.

I have learned that it takes some time for a "converted tank" to resettle under the new conditions without a skimmer, but certainly will settle in nicely. I have figured out that the results of waiting six months with a new set-up with nothing in the tank but live rock and sand is well worth the wait. I have learned that we grossly underestimate the power of live rock and live sand's ability to handle nutrient loads.

Phytoplankton helps these tanks a lot - as a food source and in water purity. Water changes are no more and no less needed than in traditional tanks, but are still beneficial for many reasons inherent to all closed system aquaria. I am about to embark on some fairly detailed water analyses, especially involving O2, as I am curious as how these compare to natural reefs. I also would like to measure calcification by alkalinity depletion.

Advice to those considering pulling their skimmer offline? Sure, why not? Just do it.

But make sure your system and your abilities are "up to snuff." I think skimmers or "ATS" filters provide a safety net for beginners, immature tanks, or ones that started off without much thought. There should be nothing scary or intimidating about it. In my eyes already, and having seen so many others follow along, I am reasonably comfortable saying it is not much different that when everyone started "pulling the plugs" on their wet/dry filters. Lots of trepidation out there right now, and pretty much unwarranted, in my experience. Obviously there will be those who try and fail. Of course, the same can be said of any "technique."

The key, I think, is spending more time looking at the tank and less time messing with equipment - it really makes reefkeeping a lot more enjoyable! However, if you are happy with your tank and it is doing well, leave it alone. Please don't go rushing off to do it just because you think its vogue. Bad motivation. My motivation was inherently the fact that I was dissatisfied with what I saw in my skimmed tanks - they were too sterile looking too unrealistic.

Is it the way? Of course not. But, IMO, it¹s a good way.

If you think an unskimmed tank is for you, but are concerned about your particular abilities or situation, try a small version, instead. A five or a ten gallon tank on a shelf somewhere with some fragments, algae, and some small gobies is an excellent way to become comfortable with running a tank without a skimmer - and very easy to water change if things go wrong. A new friend of mine in Houston was over a few weeks ago and made the comment that this tank was definitely one of the simplest working systems he had ever seen. It really is.

And what's really neat is that the corals are quite literally growing out of the water. Hard to ask for more than that! But, there is still much to learn and much to do, and this is just a step, I think, on the way to still grander things. I hope you found something useful here tonight, and I'll be happy to answer any questions.

Q&A Session:

would you recommend setting up a tank without a skimmer or pulling the skimmer after the tank is stable?

Ideally, I think setting it up from scratch is a better way. Both seem to work, though I think there needs to be sufficient modes of uptake (and export, if needed) first.

Was the plenum divided into layers or just live sand - one single layer of sand that is.
In this tank, the sand bed has always been screened. However, I did this mostly because of the potential that I may have added deep burrowing animals like Valencienna sp. etc. - I would not screen now, although the Alpheus could be considered in that category It depends on the animals present as to its utility, I think.

Follow up to first question: What sort of uptake were you referring to...aka algae removal? and: What are the modes of uptake that are so important?
Well, uptake is involved in many forms - the macroalgae, short algal turfs, plankton, benthic flora and fauna, bacteria, corals, sponges, etc. In other words, a brand new tank with a heavy fish load and some fairly barren rocks is probably not ready, IMO

How do you know there is phytoplankton, given surface/volume ratio of a fish tank, it seems surprising.
The phytoplankton is there because I add it regularly. It is also unlikely that some amount does not exist naturally.

You actually believe the biofilm on top of your 40 is beneficial, and make no effort to remove it?
I'm sorry - I don't remember mentioning biofilms at the water surface or that they were beneficial? Elaborate please?

"Water movement, especially without a sump for water to fall into, is perhaps even more important than in tanks employing skimmers. Biofilms play a more naturally important role here. In general, these systems look and act much more like a natural reef." - That is the context it was taken out of I believe Eric.
I mention biofilms earlier in terms of their presence on substrates. They seem more evidient and easily exploited in unskimmed tanks than in skimmed tanks - I suspect because of the availability of msubstrate material in the water column - dissolved and particulate Hence why i find water movement to be imperative in this tank no, there is no sump on this tank, or no surface extraction - the water surface is vigourously agitated and remains free of film.

Followup again: Do you have any problems maintaining adaquate dissolved O2 in your tanks without skimmers or algae scrubbers?
good question. I have just ordered a set of Winkler's tests on this account. This is an area I look forward to exploring, but based on the long term health of the tank, I question if there is a problem. The water motion seems to be adequate, and previous use of relatively useless O2 tests kits indicated near saturation values - I don't really trust tetra, though, hence why I am getting real tests for O2

I have black spots in my sand and was told to siphon them out...should I? what is it?
I don't think it will be a problem - this is probably an area characterized by reduction processes - normal occurrence and very efficient one, too. They should go away as fast as theya ppear. If you perturb the areas, you chance relasing some H2S into the tank - that would be potentially a problem. Leave the areas alone, IMO

Why do you think the quality of live sand has gone down so much, and who still ships "the good stuff?"
pt 1: because of both collection and shipping methods - and $$$ - the live sand I originally bought cost darn near as much as live rock - over 4.00 a pound. pt.2 - not a clue. best method now, i think, is to use the commercial "detritovore" kits or the like - or collect your own if possible and legal

Why did you stop adding strontium and iodine, are you running a calcium reactor to make up for those lost elements, or water changes?
I still do water changes. There is no good evidence to support the need of strontium in reef tanks. Iodine is good for brown algae and antipatharian axes. Everyone else (vertebrates, crustaceans) gets iodine through my food mix. Other than that, I'm not aware of a need for iodine. no calcium reactor.

In your tanks without pleneums, do you try to leave a lower level of sand undisturbed for nitrate reduction, or is it ok to have the whole thing stirred? I ask because I am considering getting an engineer goby, who will stir down to the bottom
Nitrate reduction can take place in many areas - even ones with oxygen! It occurs within sand grains, in the live rock, etc. Clearly, the more substrate available for such processes, the more will occur. I think if you want a burrowing animal that attempts to separate static from "burrowable" areas be tried

By "iodine through my food mix" do you mean you add iodine to your food mix or is it just whatever iodine is present in the food?
I use six different types of algae in my food - several of them are high in iodine - Dulse, for example

Do you think seagress is an efficient nutrient exporter ?? What kind do you have/how do you root it ??
It seems very effective and there are many studies to support this - however, much of their ability is in the communtiy they foster, including micorbes near their roots - I have Synringodium filiforme and Thallasia testudinum It is rooted in 8" fine sediments and carboinate muds Thallasia is a climax species and is slow growing - takes a few planting to get it right, IME, and they do not tolerate dessication.

Fine like oolitic or fine like silt ??
both - I used a base of oolitic and then collected very fine silty carbonate muds from their location - mostly well worked upon Halimeda plates It is very soft and "mucky" fwiw, seagrasses and their sediments stink to high heaven out of water :-)

What's a "patch reef community"?
I have a few small outcroppings of rock among the grasses with various macroalgae (mostly halimeda, Peniciillus and Avrainvillea sp.) and patch reef type corals - lagoonal Acropora, pocillopora, Pectinia, gorgonians, Porites, Hydnophora, Catalaphyllia, Siderastrea, etc.

Any tips for growing Gonipora?
not a one :-)

How long was the moving time of the tank? What was that like?
Long long story - another time - over twelve hours in 100 degree plus heat - a nightmare move - most of my other moves were tiresome but very successful. Moving truck broke down twice and the cigarette lighter that powered my A/C inverter didn't work plus power at new house was not turned on and had to go buy a generator sigh

When is the new book going to be out?
you would have to ask my publisher - it is in his hands and I would like it to be as soon as possible

A number of people have wanted to know if you have a web-site where they can see pictures of your tanks. Do you have one?
I am working on it - lots of kind offers from many, and I may take someone up on it - I want to upload a long list of references for all and put tank shots on it

Thanks for the great talk, Eric!

Created by liquid
Last modified 2006-11-24 13:06