Raising calcium levels

[fish therapist]

My yr old 30 gallon reef tank can't seem to keep the calcium up.I test weekly and all top off water has liquid calc. in it.Anyone have experiance with the instant ocean salt mix being low on calcium cause I had used coralife before and calcium levels where high then.With all the caclium supplements I've only managed to get it to about 250-300 ppm range! But My hard corals are still thriving and growing like crazy.I'm also starting to think it's my test kit which is a Red Sea mini -lab.And I also do frequent small water changes.Anyone have exp. with these test kits or salts causing this please share.But hopefully any day no my sump will be built and I'll be able to drip kalk in which is bound to work.And the current liquid calcium mix is by red sea also since the kent product before didn't seem to be working.

 

[nss11110]

i use instant ocean and my cal. is allright.. get a different test kit and retest, could be bad kit.

 

[psumba]

I use instant ocean and I dont have a problem.
In fact my recent catastrophe was I put in too much and didnt have a high enough alkalinty and my pH dropped. be careful.
If your corals are doing well as you describe, maybe they are pulling alot out of the water. How many corals are we talking about?
How often do you add? Are you following Kents instructions of a capful per day per 55gals?

 

[fish therapist]

I think I'm gonna try another test kit.I seem to find it hard to believe with the corals doing so well and the frequent water changes that it could be that low.I'm also gonna test my fish only tank that doesn't recieve any supplements and see what that says.