Low Calcium

[Restless10101]

Hey all

First time poster.

I have a bit of a head scratcher, but I cannot get my calcium levels above the 380 mark. I have a 46 gallon Tanks with (approx.) 15 gallons in sump. Here are the water parameters:

Ammonia/Nitrite/Phosphate : 0
Nitrate : <5
Alkaline : 10
PH : 8.0 - 8.1
Magnesium : 1300
Calcium : 380

I've been manually dosing my tank with 15 ml/day of C Balance (Two Little Fishies) and has maintained a calcium level of 380. Not great, but in the acceptable range. Yesterday I tested my calcium and it was 360 and the Magnesium was at 1200. Added some SeaChem Magnesium and tested this morning and the level was at 1300. Added 1/8 teaspoon of Kent Turbo Calcium and tested a couple hours later and my calcium was at 380. Added an other 1/8 teaspoon of Turbo Calcium and retested the calcium 5 hours later and had the same result of 380.

Any advice would greatly appreciated!

[Aquattro]

Always retest with a different kit when you get weird numbers. See if you can duplicate the results.

[craigwmiller]

+1 - check against another kit, both CA and Alk. It *could* be that your alk test kit is waaaaay off instead.

Further questions:
- what salt are you using? (Purple lid Instant Ocean has low ca/alk/mag)
- what salinity are you mixing it up to? (normal 'reef' would be: 35ppm == 1.0265sg == 53ms)
- what equipment are you using to measure your salinity?
- when was that equipment last calibrated? how?

[monza]

I'd guess your tank is consuming that amount your dosing. Double dose calcium for a couple days and see what that tests like.

[gregzz4]

I'll agree with 2 points

Check your kit against someone elses and if that doesn't help, try double-dosing your tank for a day to see what happens

Because your Alk is so high, I'd think you're going to have issues bringing you Cal up

And because your Mag is lowish, it may cause issues too

I'm not saying 1300 Mag is low, but your params are out of balance, so it'll take you time to get things together

If you keep having issues bringing your Ca up with your higher Alk, I'd recommend you boost your Mag
Then you may have an easier time balancing your Ca and Alk