ALK high, CA low

[Reef Man]

Hi Randy,

I seted up my reef tank 2 months ago.

One week ago I tested my water and all was normal, except CA.

Ammonia=0
Nitrite=0
Nitrate=0
PH=8.2
Alk=10.9
CA=220

I bring my animals from my friends tank two weeks ago, because he has to empty it. He keep my livestock until I setup this tank.
From the past week, I tested and I had the same parameters, except for the alk=13 and CA=220.

I have 1.5 weeks adding kalkwasser every night (one gallon) and on the mornings, I am adding just the Calcium part of the B-ionic system.

The testing is on the same way, alk=13 CA=240.

What can I do to correct this?

I have the following setup:

50 gal custom tank,
10 gal sump
MTC beckett skimmer with MAG 12
MAG 7 as return pump
2 powerheads inside tank
1 MH 250 watts
1 squid on my return line
Carbon from TLF and Phosban

livestock
2 false perculas
2 branch hammers
1 frogspawn
2 Ricordea mushroom
2 sarcophyton
1 pavona
Clavularia
GSP
some zoos
6 snails
5 red hermits
some xenia
1 colt
1 sinularia dura

Thanks in advance for your help.

[Randy Holmes-Farley]

Assuming the calcium kit is accurate (perhaps check your salt mix to see if it is working OK), then I'd boost the calcium with calcium chloride, then not add anything that is buffer only (like a pH control agent, etc).

These may help:

Reef chemicals calculator
http://home.comcast.net/~jdieck1/chem_calc3.html

Solving Calcium and Alkalinity Problems
http://www.advancedaquarist.com/issues/nov2002/chem.htm