Very low Calcium levels

[windcoast reefs]

Hey everyone,

So I started running a doser last weekend and my calcium is really low. My alk is at 10 (where it always has been) and my magnesium is at 1250, but my calcium is at 240. Any ideas on how to correct this?

Im currently mixing up a 30 gallon water change that I will do tomorrow. Not really sure is there is anything else that can be done, any suggestions?

[daplatapus]

A couple quick questions come to mind:
What salt are you using?
What are you dosing thus far, how much and when?
What's your tank size (total water volume) and composition (sps, LPS, clams etc)?

[Enigma]

What test are you using? Have you compared it to a known sample?

[windcoast reefs]

Originally Posted by daplatapus

A couple quick questions come to mind:
What salt are you using?
What are you dosing thus far, how much and when?
What's your tank size (total water volume) and composition (sps, LPS, clams etc)?

Ive been using instant ocean for the last year and a bit, and I do water changes every week (25 gallons)

Im dosing seachem reef advantage (approximately 12 teaspoons in 1L) and brightwell alkalin8.3 (14 tsp in 1L) spread out over 1 week. Also I use a low concentration of kalkwasser in my ATO to even out any alk swings.

It is a SPS based tank, and I have only manually dosed in the past. 80% of my corals are still frags.

[windcoast reefs]

Originally Posted by Enigma

What test are you using? Have you compared it to a known sample?

I use ELOS and API test kits, both read out exactly the same. I compared this to my freshly mixed saltwater which is testing at the correct levels.

[Aquattro]

Don't kill those frags!!

[windcoast reefs]

Originally Posted by Aquattro

Don't kill those frags!!

Lol I think they will be okay for the night!

[FragIt Dan]

Are you adding the Kalk slowly? Adding it too fast can actually pull your Ca down rather than push it up. Also 240ppm Ca seems impossibly low, I would double check that result.
Dan

[reefwars]

Originally Posted by FragIt Dan

Also 240ppm Ca seems impossibly low, I would double check that result.
Dan

absolutely

[windcoast reefs]

Originally Posted by FragIt Dan

Are you adding the Kalk slowly? Adding it too fast can actually pull your Ca down rather than push it up. Also 240ppm Ca seems impossibly low, I would double check that result.
Dan

Double checked 3 times with elos, and twice with API test kits.

It is a very low dose of kalk. My ATO only adds 5 gallons of water a week and only has 2 tablespoons in the 5 gallons of water. It has never given me any issues before (started doing it 4 months ago), my levels have been pretty stable up until now.