calcium spike???

[Dozer]

This may be kind of long, I'm sorry!

Last week I accidentally dosed too much Kalk I think. I put too much in a dispenser and it all went to the tank over a period of several days. I didn't think much of it because the tank looks really good. The only problem I noticed is that I think it drove down dKH and drove up pH (pH was reading near the top of the test kit, dKH was down around 6). To correct this I added some dKH Super Buffer and brought the kH up to between 8-9 and the pH down to around 8-8.2 over 24 hours or so. About 24 hours after that (which is today), my smallest (and newest) fish, a 1.5-2" sailfin tang started looking bad. Kind of pale color and worst of all, acting real limp and almost laying down at times. I've been watching it but it looks bad. I tested and double tested all water params and everything that I can test for looks great (Amm, Nitrite, nitrate all 0)- except for the Calcium is possibly way way too high- it's registering in the 800's. Now, I must admit I don't really trust this kit, it's cheap and I've never liked it and I swore it gave me false readings before, so I'm not totally convinced it's that high. However, I know I overdosed Kalk so I wouldn't be shocked if it is really high. Also, all corals showing no ill effects (some SPS, some softies), anemone looks fine, all the other fish look fine (large maroon clowns, naso tang, yellow tang, green wolf eel). I guess here are my questions at this point:

1) The Kalk was dosed by a Tunze dispenser, in top off water via Osmolator pump. Assuming I dumped too much in the dispenser, is it possible to overdose just on top off water like that? It's probably topping off about 2 gallons per day, on a system with 150 gallons total water. Maybe I didn't even overdose and I'm way off here? We never saw any kind of cloud or anything, the only reason I assumed I overdosed was because when I checked things a few days later the pH was so high and the kH was lower than normal and the kalk was all dispensed so I guess I assumed I overdosed it.

2) Since I can't get an accurate Calcium reading at the moment, are there any other signs I can look for that Calcium is too high? Would certain corals look a certain way or something?

3) Is Calcium shooting so high like that really dangerous in and of itself, or is it just dangerous because of what it can do to pH?

At this point I'm guessing the Calcium shot up, knocked kH and pH down, and then I brought kH back up and pH down, and that whole process stressed my sailfin and it's now feeling the effects. However, as I said nothing else is showing any signs of stress at all. I guess one leather looks not so great, but not really that bad either.

It should be noted that I have only had the sailfin for a few weeks- maybe a month- and it's possible it was cyanide caught or something and maybe was not meant to survive real long anyway- and it's demise has nothing to do with this kalk situation. The sailfin has always looked ok, never real great, never terrible. I don't want to jump to conclusions, but I want to protect the remaining inhabitants.

Any thoughts and suggestions for immediate action (if anything) would be appreciated!

[GaryP]

Mike,

I think the stress of changing water parameters on top of being newly introduced is the culprit here. Tangs always stress when moved anyway.

As far as evidence, besides your test kit data that your calcium is high is right there in front of you. The low dKH is it. Wheter you saw it or not, you precipitated some calcium carbonate. When you raise the pH, the solubility of calcium carbonate goes down. You made some sand. I would recommend servicing your pumps. I would suspect that you have a fair amount of scale built up inside the impellors cavities. Precipitation always starts in the pumps first. They may be running OK now, but the next time you shut one down to do a water change or something else it won't start again. I know that usually results in water on the floor at my house.

Adding buffer now is probably only going to create more scale until the calcium gets lower. You have 2 options for lowering the calcium, precipitating it out with buffer and dealing with the problems with the pumps as I mentioned, or by doing several water changes.

HTH

[Dozer]

thanks Gary, that does help. Are there other likely places that I can look for precipitate also besides pumps?

Besides the pump issue, which method do you prefer in terms of lowering the calcium- and over what time periods? I am going to take a sample to at least one LFS tomorrow also and verify how high the calcium really is before doing anything more at this point I guess.

[GaryP]

Water changes are probably the best way to getting your system back in balance. I don't know what salt you are using, but a higher buffer, lower calcium salt like IO might be better in your situation. I wouldn't try to do it all at once. Weekly 20% water changes should be good. Of course I would recommend doing a lot of testing and keep a close eye on scale build up in your pumps.

[Dozer]

I usually use Oceanic, so either I'll change out less at a time or get some IO just for this situation.

I'm still ****ed at myself that I did it in the first place :angry . Stupid mistake.

[matt]

No way do you have calcium in the 800 range; it's simply not possible at anything close to normal ph. Besides, KW does not increase calcium that much, and it definitely does not lower carbonate hardness. The real danger with overdosing kalk is a ph spike.

It really sounds like you need to invest in some new test equipment; Salifert for calcium and carbonate hardness, and a hand held ph probe with calibration fluid. Start with this step; until you really know what your readings are, you can't really do much except maybe make it worse.

If you dosed a couple of gallons of KW into a 150 gallon system over a couple of days, that's not overdosing as long as it went in slowly; I used to dose 2 gallons a day into my 45 breeder. Kalk powder is not particularly soluble in fresh water, so the KW reaches saturation and there's usually left over powder on the bottom of your top-off tub.

Get a ph probe!

[Dozer]

Thanks matt, you make some good points. It's been in the back of my mind that maybe the sailfin's problems were unrelated, but it's so frustrating not knowing. It did go in slowly from the Tunze calcium dispenser and Tunze Osmolator in top off water.

Of course if the calcium turns out to not be that high then the pH probably didn't swing that much and since the other water parameters seem very good- and everything else in the system seems healthy- I would be at a loss as to why the sailfin died. I would have to suspect that it just wasn't super healthy I guess, or got stung by something else in the tank maybe.

Now I can't decide if something happened in my tank or not...

[Tim Marvin]

I'm with Matt on this. If you read 800 it would look like a snow flurry in your tank. How much kalk dosed? If your talking 4-5 tablespoons in the tunze that is hardly worth talking about, and you should be just fine. Oceanic is high in calcium, so I would take it easy on the kalk unless you get a bunch of stony corals or coralline growing like crazy. At any rate, I am sure you are OK if it is just the one fish you may just have a problem with that one. Let us know if you see anthying else that looks strange.

[Dozer]

Thanks Tim. I had a feeling that test was junk, so it wouldn't surprise me. The water is very clear. 4-5 tablespoons is probably about right, maybe a little more. I guess when I saw the pH so high and the kH had fallen a little I assumed. Now I wonder if the pH test was even accurate :unsure .

I need to get hold of some better testing equipment like Matt said. In the meantime I'm going to watch everything and figure out a way to get an accurate reading on the Calcium and not dose any kalk until I figure it all out.

Thanks everyone for all your help. Now I'm starting to lean toward that little sailfin just not being healthy for some other reason.