Ok, can you explain "ionic imbalance"??? When I hear this I think of Marty Feldman pouring chemical in a vile and screaming "It's ALIVE!!!!" I understand the basics, but would really like more on the interaction between alk/ph/ca and the causes for imbalance.

First, let me declare that I am NOT an expert on chemistry. I barely passed Chem101 back in College ;-)

Most of the information is gained from my war scares with "sand clumping". And of course, anyone who feel there is a need to correct my mistakes, feel free to jump in and correct them.

But, since Michelle asked the question, and with the whole Mg thread that is going on, I would just like to share what I have learned in the first couple of years on my "chemical warfare" experience. ;-)

Okay, first of all, some of the basic number for NSW, and these are averages and not for an given ocean. TRA 1 and TMCRA 1 both has info on these numbers.

• GS 1.025 ppm
• pH 8.2
• Alk 7 dkh (2.5? meq/l)
• Ca ~412 ppm
• Mg ~1310 ppm
• plus many others

Now, keep in mind that these numbers are basically the numbers we in the hobby generally knows and measure. However, there are plenty of "other" numbers that we dont know, or cannot measure w/o having to spend $2000~$5000 and get a Hach spectrophotometer (or is that photospectromemter, Mike K, knows this better then I do, hee)

Okay, now to the core of this whole issue, IME and IMO. Part of the problem is that many hobbyists' good hearted advice is they generally just ask you what is your pH, Alk, and Ca. After knowing these three numbers, they then tell you go buy this and go buy that, go add this and go add that, and your pH, alk, Ca problem will ALL go away. But this turns out to be one of the biggest mythinformation I have come across thru out the whole internet.

What usually ends up happening is the person seeking the advice follow the instructions and come back with more problems. Why? Because they are trying to fight a chemical warfare w/o knowing all the players involve. What are all the players? Well, the above NSW figures, plus tens, if not hundreds, of chemical that exists in NSW. The best part of me yet, is after having some serious exchanges with Ron S. on sandbeds, I find out that he doesnt even add any chemicals beside kalk water in his three systems.

An example of this is ... B-ionic ... If you use it all the time, it will stabilize your pH, alk and Ca. But at the same time, you better keep track of your SG (read the warning on their label). It happened to me when I was fighting my fight. With my 120 gal tank I was adding 30 ml per day, per instruction, trying to bring my Ca level up to 400 when it was at 325. When I started, my SG was at 1.023, two weeks later, it was at 1.030 !!! What most two part Alk/Ca additives do is they generate excess chloride and sodium. Since SG measures the total ion in the NSW, the reading is of all the chemicals together as one. Now, since the "water" volume didnt change, it changed what made up the "water".

When you add salt into your fresh water, those salt disappears into thin "water" (couldnt use air, hee). So, where did those salt go? And man, they are heavy !! But poof, all gone just because you mixed it? Well, those salt are "ions" and they all interacted with the fresh water and became part of the water.

Now lets move on to the imbalance part of the fun. For me personally, this whole thing started when I was using CraibSea aragonite sand, w/o LS, and trying to allow the sand bed to become an A/N/N filter. Little known to me back then, and CaribSea themselves, that aragonite also are the prime reason why your sand can clump as hard as a rock and hender the sandbed totally useless. (Further reading can be found about related sandbed discussion in the archives on www.mjcrealm.com , do a search on "sandbed" ) This is due to the fact that aragonite is a prime receiver of Ca and causes the aragonite to clump. As we can see, this Ca must come from somewhere, and that somewhere is what you added into the water. The funny thing is the more you add, the more it happens, and sooner or later your whole sandbed will become nothing but a solid slab laying on the bottom of your tank. So I researched further and found Sam Gambel's series of articles on Aquarium.net. He has 3 or 4 articles just on clumping.

My understanding of his reasoning for all this is because if you are adding too much of something, it will cause the excess "ions" to over take or cause some reactions to happen and end up causing an "ionic imbalance" in your tank. Ie: the low Ca, low alk, or low pH problems we all have been reading about. This happens is because the excess ion is suppressing the other ions in the water and hence prevents the natural balance to be achieved. Just picture this, no matter what you add, you have a total water 100 gal. If the natural ionic balance is 50:25:25, and different reactions will occur if the ratio is changed to 25:50:25 or 25:25:50, something is bound to go wrong and you wont get your 50:25:25 ratio again no matter how much chemical you add into your tank. Because no matter what, the total water is still the same 100 gal. This is also why water changes is the best fix to any of these problems. Because you are removing the excess ions and replace the water with NSW level content.

So now, if we keep the alk at say 15 dkh, which is higher then NSW, something in that water must be lower then NSW. Also, if we keep Ca at 500, or pH at 8.4, and SG at 1.023, what other "content" is off balance? The same question applies to all the chemicals we add into the water. This is how and where one can cause an "ionic imbalance" for a given tank. ;-)

Right now my system has been maintained by a Knop-C kalk reactor for the past 4 mos. I now have coralline algae growing all over the glasses. The once fully pinked covered but gone bared rocks are now in the process of recovery. My Ca, Mg, Alk readings? No clue. My corals? Fully opened every day. The last set of tests that I done was back in late March.

Anyone else is more then welcome to add what they can share to further the knowledge base of all of us.

Well, sorry for the long winded replay. Hope this is of any help for someone ... ;-)