calcium help

[bubbaque]

My calc seems to drop a lot each day. I keep a daily log and have been testing for calc and alkalinity each day because my calc keeps dropping. Yesterday my calc was 430 and today it is 380.

My alkalinity has been pretty stable at 10 - 10.5. My magnesium was low but I have been bring it up and now is stable at 1350. I have been trying to read some articles about calc dropping but I am mostly find that alkalinity drops and calc doesn't.

I do not have much coral. I have a three sps frags, hammer coral frag and small Zoa frag. Any idea why calc drops much faster then anything else?

 

[Randy Holmes-Farley Verified Community Expert]

My calc seems to drop a lot each day. I keep a daily log and have been testing for calc and alkalinity each day because my calc keeps dropping. Yesterday my calc was 430 and today it is 380.

My alkalinity has been pretty stable at 10 - 10.5. My magnesium was low but I have been bring it up and now is stable at 1350. I have been trying to read some articles about calc dropping but I am mostly find that alkalinity drops and calc doesn't.

I do not have much coral. I have a three sps frags, hammer coral frag and small Zoa frag. Any idea why calc drops much faster then anything else?

If the alk did not drop, and you are not adding any alkalinity, the calcium did not drop (unless by water change). If 50 ppm of calcium was consumed, alk MUST drop by about 7 dKH.

Consequently, if you are not adding alk, it is likely the effect you are observing is testing error.

50 ppm is also too large of a calcium drop to be real in any reef tank in one day.

 

[bubbaque]

Thanks for your reply. I just tested again and I got a reading of alk at 10 and calcium at 420. I will test again tomorrow and see where it is at.

 

[bubbaque]

Thanks for your reply. I just tested again and I got a reading of alk at 10 and calcium at 420. I will test again tomorrow and see where it is at.

I hope the API test is not bad. I have been adding calc to keep it up.