Calcium is suddenly low

[B-Man]

Suddenly may not be the best term. I normally only check my parameters every 2 weeks or so because they have been very consistent in the past. This past weekend I checked my Calc and Alk, and both had dropped considerably. I normally ran at 410 - 440 ppm Calc, and 3.6 meq of Alk, after my last test I was at 340ppm and 3.0 meq. My Salinity is steady at 1.026 and I have been using Kalk for all my makeup water.
Any Ideas on what could cause this drop? I would like to raise my calc again, and I have some Calcium Chloride, but I don't know the best way to add it. Do you just add the "pellets" to the tank or should I dilute it in some water and drip the liquid into the tank? Please help me to understand how to add the Calcium Chloride to my tank. Also should I continue to use kalk while I am trying to raise the calcium without raising the alk? My tank is 65 gal. and has about 7-8 sps frags (I did not think that they would have used that much calcium - especially using the Kalc).

[Randy Holmes-Farley]

B-man:

Any Ideas on what could cause this drop?.

None that fit that situation real well. The calcium has dropped a lot and the alkalinity not so much. That is unusual if there are no calcium or alkalinity additves being used except perfectly balanced ones (like the limewater). Maybe one (or both) of the kits is in error.

Here are some possibilities that may have caused a drop in both:

1. An increase in calcification by the tank organisms.

2. A decrease in the limewater concentration.

3. A decrease in the evaporation rate, and hence less limewater.

4. An increase in tank pH, that is resulting in precipitation of CaCO3.


Do you just add the "pellets" to the tank or should I dilute it in some water and drip the liquid into the tank?

Dissolve the calcium chloride in some water (doesn't take much) and add that liquid. No need to drip. It will take a substantial amount to raise the calcium level.

In your case, it will take about 50 grams of anhydrous calcium chloride to raise the calcium level from 340 ppm to 410 ppm.

Keep up the limewater at the same time. You don't want the alk to drop.

[B-Man]

Thanks Randy,

The reason I asked about how to add the Calcium Chloride is because I thought that was how it was supposed to be done. I tried it and I had what appeared to be precipitate or "snow" when I added it to the tank. I'm leaning more towards the idea that the test kit's are bad. I'm using a Hagen kit for Calcium, it's all I can get around here and I cannot Mail Order over the internet here at work (my only internet access). Have you had any experience with these kits and how reliable they are. If I can get my hands on a Salifert kit, how accurate are they? What I can't figure out is why my kit read 410 and just one week later read 340ppm, can a kit go bad that fast? I thought it would be a more gradual decline.

[Randy Holmes-Farley]

I've neither used Salifert kits nor Hagen kits. From what I hear from others, the Salifert kits are good.

What I can't figure out is why my kit read 410 and just one week later read 340ppm, can a kit go bad that fast?

It's not likely to go bad in one week. It might not be a very reliable kit in that 2 tests at the same time might give different answers.

[B-Man]

Actually it's pretty repeatable. I have tried multiple tests when I was trying to confirm if it was the test kit, I have never really trusted them but it's all I can get. In the last 3 days I have run at least 6 tests and they are all at the 340. In other words it's precision is pretty good, I'm just questioning it's accuracy.

If I'm seeing the precipitate when adding Calcium Chloride:
1) Am I risking a crash in my Calcium levels, or is this normal
2) Should I just assume that my tester is bad, I'll looking at getting a better kit.
3) Would it help to do some major water changes?

[Randy Holmes-Farley]

Am I risking a crash in my Calcium levels, or is this normal

IME, it is not normal if the calcium chloride is disslved in water.

I've never used CaCl2 myself, but using B-ionic would be similar, and I've never seen a precipitate from the calcium portion.

[B-Man]

Thanks for all your help.

I guess I'll have to see if someone around here can do a test for me to confirm.

[goldrimtang]

Hi B-Man,

I have one thing to add here. I had the Hagen Calcium test
(actually part of its master kit) and then I switched to the
Salifert brand. I can assure you that the difference is huge. The readings are way more accurate and it's easier to do the tests with the Salifert.

I live in Canada, but here in Vancouver we are lucky enough to have J&L acuatics to provide with the stuff reefers need, like Salifert test kits. If for whatever reason you can't order on the net, give them a call and they will take you order on the phone.

Hope it helps,

Emil

J&L : http://www.jlaquatics.com/ 888-840-1146 / 604-1146

[deukmedjian]

Marine Depot has the Salifert and Seachem kits very cheap and you can order over the phone.