Calcium levels dropping...Need help!

[rubiconman]

I am having a problem keeping my calcium levels at a sufficient level. I am currently adding Kent pro buffer parts a&b daily, but my levels will not get up past 300ppms. This morning I added 12 mls of both units to my 55 gal. and tested several hours later and they were 50 ppms lower than they were this morning before adding. Last Sunday I did a 20% water change and then tested the levels at 450-500ppms. Then a day later I checked it again and I was under 300ppms. I do have a calcium based calupera growing crazy and wondering if it is eating the calcium up. Is this true? This has been going on for several days now and I can't understand what is happening. Therefore, I am calling on the professionals. I currently have 12 fuzzy mushrooms, 1 red mushroom, green star polyps, and a 12lb. live rock that came with several unidentifiable coral colonies.

 

[Anonymous]

Low Magnesium IMO.

Can you post your ALK & Calcium levels? I suspect you're trying to maintain an ALK level that is too high. Do you have a Mg test kit?

 

[rubiconman]

I currently am using a Red Sea Alkalinity test kit and it only reads low, normal, and high and currently testing at a normal level. I do not have a magnesium test kit, but if you think this may be the problem I will get one tomorrow. Can you tell me the correct levels to look for?

 

[Anonymous]

1250 - 1400ppm for Magnesium. When Magnesium drops low the water can't hold as much Calcium. It wouldn't hurt to get an ALK test that will give you numbers. "Normal" is kinda meaningless.

It your calcium based calupera really Halimeda? Halimeda can definately consume Calcium but not at the rate your calcium is dropping. Going from 500ppm to 300ppm in a single day usually mean it's precipitating.

You can also check you heaters to see if there's any crusting on them. That usually the first place Calcium carbonate starts to precipitate.

Also, I should mention that when Calcium precipitates your Alkalinity will drop fast as well. Having Calcium drop from 500ppm to 300ppm will, in theory, drop Alkalinity from 11dKH (normal) down to 0.