Surprisingly Low Calcium Level

[raylinds]

I started cycling my tank about a year ago. I have a thriving small community of fish. I have had a struggle with green hair algae that I am finally getting under control with a GFO reactor and additives that have brought the level of Phosphates and Nitrates to near zero.

I was about to start adding coral when the pandemic hit, so there is no coral in my tank yet. I had not been checking calcium levels regularly since there were no corals. Recently I noticed my coralline algae had stopped spreading, so decided to check all of my levels.

I was shocked to see that my Hanna checkers showed Calcium at 305ppm and Alkalinity at 6.2. I tested twice to be sure. How can a tank with no coral and regular water changes be so depleted of calcium? My tank system is 145 gallons.

I immediately ordered a balanced two part system and calcium chloride. What is the best way to increase calcium fairly quickly? I am doing a water change as I type this.

Thanks in advance- Ray

 

[raylinds]

Oh, pH is consistently around 8.2

 

[Snoopy 67]

Coraline Algae will suck up Calcium

 

[nereefpat]

Yes coraline can consume alk and Ca. There are also biological processes (besides algae) that consume both, as well as abiotic precipitation.

If you don't have coral, you can bolus dose alk and Ca. Mix up enough baking soda and RO to bring the alk up 1 dKH or so, then slowly add over the course of a day. After that, do the same with CaCl to increase by about 100 or so.

 

[raylinds]

Thanks for the helpful responses. I have been spending the morning reading through Randy's excellent articles on two and three part dosing. I ordered ESV B-Ionic two part and some dosing pumps from BRS, but will start using Randy's recipes to save money in the future.

 

[raylinds]

Yes coraline can consume alk and Ca. There are also biological processes (besides algae) that consume both, as well as abiotic precipitation.

If you don't have coral, you can bolus dose alk and Ca. Mix up enough baking soda and RO to bring the alk up 1 dKH or so, then slowly add over the course of a day. After that, do the same with CaCl to increase by about 100 or so.

Thanks. I will do this to get to acceptable levels and will then dose two part daily.

 

[HuduVudu]

I was shocked to see that my Hanna checkers showed Calcium at 305ppm and Alkalinity at 6.2. I tested twice to be sure. How can a tank with no coral and regular water changes be so depleted of calcium?

Never take for granted the readings you get on your tests. Check and double check, because you are making important decisions on those numbers. Maybe they are right, but what if they are wrong? I always double check my numbers when I think they are weird.

 

[Randy Holmes-Farley Verified Community Expert]

I'm highly suspicious of the calcium level.

What salt mix are you using? Ever test it with that meter?

Most mixes cannot get to the values for alk and calcium you claim from their normal starting points.

 

[raylinds]

I'm highly suspicious of the calcium level.

What salt mix are you using? Ever test it with that meter?

Most mixes cannot get to the values for alk and calcium you claim from their normal starting points.

I am using Instant Ocean, I am going to mix a fresh batch today and test with the meter.

 

[Randy Holmes-Farley Verified Community Expert]

I am using Instant Ocean, I am going to mix a fresh batch today and test with the meter.

Sounds good.

 

[dadnjesse]

Check your salinity.