HELP! - Calcium, Magnesium and Alkalinity very low

[twiddledog]

have a 72 gal reef with about 100lbs of live rock, 100 lbs of southdown sand and a 20 gal fuge.
My rock is losing its color going from a nice purple to a light violet.
I was adding calcium for a few weeks with no rise and posted in forum. I was told to check Magnesium because calcium won't rise if Mag is low.
My params at that time were Mag - 750, Cal - 250
I started adding Mag over a week ago 60 - 90 mil daily with B-Ionic Magnesium and is now up to 950.
Calcium levels still hovering around 200 - 250 although I am adding 2 - 3 tsp of Kent Turbo Calcium daily, and Alkalinity is 2.75 and I am adding 1/2 tsp of Seachem Reef builder every other day.
My other params are all good.....corals are doing ok I think, athough I lost a really nice fan worm. My rock is really losing color badly.
The problem is..I CAN'T get the Mag, Cal an ALK to go any higher and I don't know why. Seems like something is leeching the calcium.

My question is why are these so low? What would be the cause? How much supplement can I safely add per day?

Any help would be greatly appreciated!

 

[Andy O]

Try this link in terms of amounts of additives to add to get to a desired level.

http://home.comcast.net/~jdieck1/chem_calc3.html

I have boosted with Turbo Cal from 350 to about 380 or 390 at one time with no problems.

 

[~Flighty~]

I would recomend bringing it up with water changes for now (test your new water to verify that it is correct) and then look at the home made additives for bringing it up the rest of the way.

If you havn't seen them already, our very own randy holmes farley is the best resource for chemistry help
http://reefcentral.com/forums/showthread.php?threadid=102605

 

[nickyblase]

I could be off, but isn't ideal Mag level in the 1200 range?

 

[Andy O]

I could be off, but isn't ideal Mag level in the 1200 range?

I think that people usually keep b/t 1200 and 1350 but I may be wrong. I think that mine was at about 1280 the last time I checked.