low Alk and Ca

[Piratefish]

I checked my water prams today using a API testing kits. My alk is 71.6ppm??? and the Ca has dropped from 400 to 380 in two weeks. PH is at 8.12 on a hanna digital meter.

I only have two emerald crabs 3 turbos and 8 narri's in the tank. All other prams are at 0.

Any input?

 

[Ulta]

Natural Sea Water Params are:

420ppm Cal
125ppm Alk
Reef Aquarium Water Parameters by Randy Holmes-Farley - Reefkeeping.com

If you are doing regular water changes that tells me that the salt you are using is low in these supplements, if not then just do water changes regularly.

The other way to go about it is to use buffers, I use Kent Parts A & B, Part A buffs Calcium and Part B Buffs Alk.
Here is a calculator that can help you with buffers:
'Reef Chemistry Calculator FV'

+1 Ccapt, fore most of this info re water chemistry comes from his knowledge :D

 

[Solarfall]

What kind of corals are you keeping? And have you had any major coralline outbreaks lately?

 

[Piratefish]

No coral yet. just a few polyps that were on one of the rocks. There has been some coralline growth over the last month, the tank is just a month old with new water and new live sand but the rock is many years old, I was given the tank that was neglected. Its a 55g with sump and algae scrubber.

 

[ccCapt]

What brand salt are you using? That alk is really, really low and I would have to wonder if it's not a testing error or bad kit. 71.6ppm = 4 dKH = 1.4 meq/l

 

[Piratefish]

I'm on vacation, will test again when I get back.
I think its correct though. I don't remember the brand of salt off hand. Red sea reef I think.
I tested it two weeks ago and it was at 125 I will have to check my notes when I get home.

 

[d2mini]

What's in the tank?

I ask because i don't care what salt you're using.... if you have stuff in there that's sucking up calcium and alk, you need to supplement. I only have a few sps and some lps and if i don't supplement, my calcium will be down to 250 and alk at around 2 dKH.

EDIT: Just saw no coral. Could definitely be bad kits. I know mine were bad recently. But still, that drop in Calc doesn't seem like much too me.

 

[yote]

If you've got a lot of coralline growth,it'll suck the calcium and carbonates the same as a tank full of SPS.But even at that every tank is different.