calcium troubles

[martym]

Here's the story. For the first 3 months my calcium was around 400ppm, alk was low around 3-4 dKH and PH was low around 8.0. I was adding KH super buffer by seachem to try and get the alk and PH up. Calcium never changed. I had no luck. Started to dose Kalk by seachem. Ph and Alk whent up 8.4 and 12 DkH calcium dropped to 200ppm. Been adding Reef calcium by seachem for the past 4 day doseing max amounts Half in morning half in evening can't get calcium above 270ppm. I though Kalk was suppose to maintain calcium, not drop it :mad: What did I do wrong, and why won't it come back up? Is there a different calcium that works better than seachem?

[StirCrazy]

is it a new tank with a new sand bed?

Steve

[martym]

The tank has been set up since mid July. About a 1" agronite bed.

[StirCrazy]

what I (and others) have found is that fresh sand beds adsorbe Ca. I also found from my testing that the sandbed will also adsorbe Mg untill if finnishes binding all the free Ca on its surface.

this will cause a Mg crash which will also cause a Ca crash. I would recomend you get a Mg test kit or see if anyone in your area has one that you could use to confirm this.

I went through this for 6 months untill I finaly bought a Mg test kit and found my Mg was at 800ppm. this level would only allow me to obtain a 230ppm Ca level and that was with my adding kalk and using a Ca reactor. Once I corected my Mg to 1300PPM my Ca went up to 450PPM.

but do a test befor you take this as the problem.

Steve

[props]

more info
http://www.aquarium.net/0497/0497_3.shtml