calcium levels

What should tha calcium levels be in a fish only with live rock tank, and a reef tank.
My level of calcuim is at 340 (fish only with live rock), and I have some of my live rock turning a litttle white along with one of my snails shell doing the same, Im wondering if it maybe be because of low calcium All other levels are ok except for nitrate was at 30. Any Idea's would be helpful
Thanks

when you say your other params are ok what does that mean? dont forget a trace of ammonia can kill fish.. As far as the calcium goes it is not as important in a fowlr but I am kind of surprised it is that low.. how often are you doing water changes? Most salt mixes are at least 400 and nothing in a fish only uses much calcium.. and I would try to get those nitrates down a bit by doing a good water change.. reef tank you would want to try and keep in the low to mid 400's.. I try to keep mine in the 440 range or so..

+1 Marcah

I can't explain the white rock but, there's no reason for you to be testing for calcium in a FOWLR tank. There's nothing in there that will use a significant amount of cal that you'll need to worry about it. And unless you're planning on moving into corals, I wouldn't be concerned about your nitrate levels either. FOWLRs are just fine with nitrate levels in the 100's, nitrate doesn't affect fish like it does inverts and corals.

If your rock was covered with coralline and you took it out of the water for only a couple minutes the coralline will die and turn white. It will grow back eventually however.

I just posted on your other thread about your rocks turning white (I said mine had this happen too due to low calcium) but I just realized I think I did take them out of the water during one water change to try to clean algae off some rock, so maybe that was what caused it. Doesn't explain the lighter colored coralline on my glass walls though.

I have a FOWLR tank and have been supplimenting Calcium for a week now, and increased actinic times to help the growth of Coraline algae. I attempted to add coral, and snails but they wither off and die. I took a water sample to the LFS and they told me my phosphates were on the boarder line of high and that's what casued it. I have taken my rocks out to scrube some of the green algae and the coraline on them turned white as well. It is starting to grow back very slowly though.