Calcium Question

[tike]

Hey Kevin,

I have an sps dominated tank. I just converted it 2 months ago although i have kept a few sps in the past. I just added about 10 frags into the tank last night and my calcium was at 390ppm. This morning it was at 350ppm . i have never had it dip that quick before. I know when all these critters start growing nicely it could very well happen but i'm thinking these guys should be in a little bit of shock right now and growing would be the last thing on the list. Maybe i am wrong but does it seem odd to you??

I will be adding on a calcium rector within the next month or two to automate things.

Oh, i currently use a two part system for calcium and alk and it has been steady for me.

Some parms from last night: cal 390, alk 10.2dKH, pH 8.3, sal 1.027, temp 77F
This morning: cal 350, alk 9.8dKH, pH 8.2, sal 1.027, temp 77F

thanks!!!!!
willie

 

[mcvicker]

I recently moved to SPS and have 7 or 8 frags growing out and I found my alkalinity falls super fast. I was using the two part addition, but then started adding kalkwasser as top off. That has reduced my dependence on the two part stuff but I still have to make an addition every few days to get my balance back in line. Hopefully there will be a calcium reactor in my stocking this year.
-chris

 

[kevinpo]

Hello,
Yes that does seem a bit of a steep drop. It could have dropped along with the error range of the test kit which might explain it. IME alkalinity usually drops faster than calcium. A tank can be maintained with two part additives for years it's just a PITA. With a properly sized calcium reactor you will feel like it is the greatest thing since sliced bread .

I see that your original numbers were quite out of ionic balance. With such a high alkalinity it tends to drive down the calcium. A balance would be calcium reading of 400ppm and a dKH of 7.3 (the average of NSW). The more these numbers deviate the more unstable they become. It can be quite the chore to try and maintain calcium at 500ppm and 12.5 dKH for an extended period of time as they want to seesaw with each dosing. I run my alkalinity slightly high at an average of 2.97 meq/L or 8.3 dKH and the calcium at 410ppm.

On another note many of the captive raised corals that have been fragged many times will not go into shock at all but start growing right away. This is especially true if they go from one established tank to another established tank that is setup with similar lighting, flow etc.

Regards,
Kevin