Help! Chemistry Question

[awillemd1]

I have been struggling, as one could tell from my previous posts, with a 90 gallon reef setup for about 9 months now. The two biggest problems I have had have been Ich and a phosphate problem caused by a bad RO membrane. At any rate my current question is one regarding my chemistry. Currently my test kits indicate that my Calcium level is 450 ppm, my KH is 8.8 dkH, and my pH is 8.0. I just performed a water change and this caused a small snow storm. I am pretty sure I caused the problem by adding too much Ca to my new water. (My IO salt usually tests in at 350 ppm Ca, so I add a little to bring it up to around 400. I didn't check it this last time, but I am guessing that I added too much Ca.)

My question is what should I do at this point? My inclination is to add some of my Kent Marine Superbuffer to bring the pH up closer to 8.4 and of course raise my KH and to do another water change to try and bring the Ca down a little. Can someone with a more experience/knowledge advise me here on what my strategy should be?

Thanks in advance.

awillemd1

[MantisFreak]

You got to see the magic of having enough magnesium. If you would have had low magnesium that snowstorm would have continued until all of the carbonates fell out of solution.

Depending on how long the snowstorm went on, your in tank readings could be VERY different than you originally thought. Or the magnesium might have saved your behind.

Put up all new test results so we can help you better.

[Biggen]

The only thing you can do to fix a "snowstorm" is to do water changes. Not only will that fix your chemistry problems, but it will also rid your tank of all that Ca that has precipitated out.

Your calcium probably precipitated out because you did add too much. With a 8.8 dKH, your should shoot for a calcium level of around 422 ppm. You over shot it by a little and that created your problem.

I wouldn't add any buffer. Fixing a pH problem by adding to the KH is a bad idea. A pH of 8 really isn't that bad anyway. I think a few water changes will straighten you out and then you can start over.

[awillemd1]

Thank you both!

I checked my chemistry when I got home from work. The new numbers are:

Ca = 435
pH = between 8.0 and 8.4 (I can't tell the colors well enough to do any better than that. I have two kits and I used both of them. One is by Red Sea and the other one is by Salifert).
kH = 9.4

Unfortunately, I don't have a kit to measure Magnesium, but it sounds like I should get one.

Thanks again!

awillemd1

[MantisFreak]

You know how much you have now----enough.

Get some test kits anyway.

[awillemd1]

OK. So the plan going forward will be to make water changes and purchase a Mag test kit. Could I just add magnesium at this point since it appears that I am on the ragged edge of the necessary amount? This presumably would help solubilize the calcium carbonate that has precipitated out.

awillemd1

[MantisFreak]

Never add anything that you don't have a test kit for.

Water changes are definately safer.

[awillemd1]

Makes sense.

Thanks again for your help!

awillemd1

[Biggen]

I agree with Mantis. Don't add anything to your tank without testing.

[awillemd1]

Which test kit would you recommend for Mag?
Thanks.

awillemd1

[MantisFreak]

I use Salifert but I don't know if that is the best one or not.

[Biggen]

Salifert is a great kit from what i hear. I use Seachem.

[awillemd1]

What about for pH? I struggle with my Salifert kit because I can't tell the exact shade of green. To try and help I bought a Red Sea kit and I struggle there trying to tell the exact color of greyish blue. Both get me in the ball park of 8.00 to 8.4, but I think I need to do a little better.

awillemd1

[MantisFreak]

The consistency is even more important. For instance, say you normally test out at 8.2 and it is consistently 8.2, then you are in good shape. I use Salifert and it isn't exact but I have not had any problems.

[Biggen]

I use Tetra Laborett for my pH, KH, ammonia, and nitrite. It's not the best kit, but it is accurate enough for those 4 things.

If you really want to get accurate, get yourself a pH probe. While they are a little costly, you won't have to play the "color game" every time you test.