Puzzling low calcium

[TWYOUNG]

I have a 150 gal. 7mo tank. No corals as yet but has 100# of dry rock, (CaribSea Liferock). I add 1500mls kalkwasser per day to maintain an alkalinity level of 9-10. ATI tests one month ago showed low iodine and slightly low manganese,vanadium and zink. At that point I started the standard base dose of TM All For Reef. Coralline algae has just begun to grow and my Calcium tests 328(Hanna). Prior ATI result was 388 while Hanna read 440 so it could be even lower. Should I not be concerned since I have no coral, increase AFR, or dose calcium. Thanks for your help!

 

[Rmckoy]

Because you have no corals calcium is not necessary at this time . But in order to get coralline algae alkalinity , magnesium and calcium are needed as well as the coralline algae it self .
you will notice once it starts to grow it will consume a higher amount of alkalinity compared to other elements

 

[TWYOUNG]

Because you have no corals calcium is not necessary at this time . But in order to get coralline algae alkalinity , magnesium and calcium are needed as well as the coralline algae it self .
you will notice once it starts to grow it will consume a higher amount of alkalinity compared to other elements

As of today my alkalinity is 9.6 and magnesium is 1340. Should my coralline continue to grow well with those parameters even if I don't raise calcium? Also, should kalkwasser normally provide enough calcium?

 

[Randy Holmes-Farley Verified Community Expert]

As of today my alkalinity is 9.6 and magnesium is 1340. Should my coralline continue to grow well with those parameters even if I don't raise calcium? Also, should kalkwasser normally provide enough calcium

Kalkwasser actually supplies a bit of excess calcium when used to maintain alk, so it is not the cause of low calcium (if, in fact, not is not just an error).

Are you monitoring salinity?

 

[TWYOUNG]

Kalkwasser actually supplies a bit of excess calcium when used to maintain alk, so it is not the cause of low calcium (if, in fact, not is not just an error).

Are you monitoring salinity?

Yes. This morning sp grav 1.025 per digital refractometer and 34.7 salinity per Apex probe. Were you suggesting tester error could play a role? I repeated it but with the same monitor and got similar readings.

 

[TWYOUNG]

Yes. This morning sp grav 1.025 per digital refractometer and 34.7 salinity per Apex probe. Were you suggesting tester error could play a role? I repeated it but with the same monitor and got similar readings. My main interest at this point is to encourage my coralline algal growth.

 

[Randy Holmes-Farley Verified Community Expert]

If you think it is around 328 ppm, then I’d raise it with calcium chloride. I’d only worry about how it got there if it goes down again.

 

[TWYOUNG]

If you think it is around 328 ppm, then I’d raise it with calcium chloride. I’d only worry about how it got there if it goes down again.

I've been looking at calcium chloride and it looks like it's going to take over a liter to reach 400. Does that need to be done gradually?