A little help with Hi Alkalinity and low CA

[cmiller]

I'm having trouble lowering my Alk below 12, and therefore, unable to raise my CA to acceptable levels Have a 28 gallon nano established for 4 months with the following parameters
Alk: 12
pH: 8.3
CA: 350
Mg: 1350
Salinity: 1.026
Ammonia:0
Corals all look pretty healthy.

I've been doing 10-15% water changes every other day for past two weeks which brought Alk down from 20 to 13, but that's as low as I've been able to get it. Using two test kits (elos and API) for reliability. Dosing 10 ml of ca part 2 Every other day with negligible increase not beyond 350. Any suggestions?

 

[tike]

Actually 12 isn't bad. If it's starts creeping up in the 15-20 range and your cal is going down, it would have to be mag. Check the mag numbers again to make sure it is correct.

 

[user 26995]

? what are you dosing for calcium? usually in a 2 part calc/alk suppliment, the part 2 is the alkalinity. I just might not understand what you mean by part 2.

and yeah, I would double check the magnesium too.

 

[cmiller]

? what are you dosing for calcium? usually in a 2 part calc/alk suppliment, the part 2 is the alkalinity. I just might not understand what you mean by part 2.

and yeah, I would double check the magnesium too.

Thanks for the replies, folks.

I'm using the B-Ionic 2 part dosing system: component 1 is Alk and component 2 is the ca

My understanding is that my Alk of 12 is what is keeping my ca down (precipitating out)
Can I increase/decrease mg to help with raising ca or would you recommend increasing my ca dose?

I forgot to mention I tested the RO/DI water I used for water changes and those Alk levels are around 6-7

 

[mojoreef]

Yes alk will take your cal out of solution but your mah will help with that. With your salinity your alk should be around 9 to be balanced. When you dose your two part just hold off on the alk part until it gets used up a bit and reduces.

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[DTECH07]

Yes alk will take your cal out of solution but your mah will help with that. With your salinity your alk should be around 9 to be balanced. When you dose your two part just hold off on the alk part until it gets used up a bit and reduces.

Sent from my SCH-I535 using Tapatalk

+1 allowing the Alk to lower naturally plus regular water changes will allow the corals to balance out better after being at 12.

 

[cmiller]

+1 allowing the Alk to lower naturally plus regular water changes will allow the corals to balance out better after being at 12.

Good advice. Thanks. Sounds like not to worry too much with alk at 12 for now just keep doing the 10% water changes and slowly keep bring it down.
Yes, I have been holding off on the alk when dosing.

I know mg and alk and ca have a complex relationship, but will raising my mg lower alk, all other parameters held constant?

 

[DTECH07]

Good advice. Thanks. Sounds like not to worry too much with alk at 12 for now just keep doing the 10% water changes and slowly keep bring it down.
Yes, I have been holding off on the alk when dosing.

I know mg and alk and ca have a complex relationship, but will raising my mg lower alk, all other parameters held constant?

No not as a direct cause of you increasing your Mag only because as your mag increase it works so that corals can absorb the alk and Ca, so it works as a needed mineral and assistant for corals to absorb Ca and Alk. Thats the easiest way to put it.

 

[cmiller]

No not as a direct cause of you increasing your Mag only because as your mag increase it works so that corals can absorb the alk and Ca, so it works as a needed mineral and assistant for corals to absorb Ca and Alk. Thats the easiest way to put it.

Cool. That's the clearest explanation I've heard. Thanks

 

[Chichas01]

here's a great article I used to understand the relationship of CA-Alk and how to get it to balance:Chemistry And The Aquarium: Solving Calcium And Alkalinity Problems — Advanced Aquarist | Aquarist Magazine and Blog
In short, pick one (CA or Alk) to get to the range you want, then start equal dosing of your 2-part. Depending on your pH level, you can use 2 different methods for this:An Improved Do-it-Yourself Two-Part Calcium and Alkalinity Supplement System by Randy Holmes-Farley - Reefkeeping.com