calcium /alk imbalance? need help

[LEGACYLINE]

I'm using brs 2 part and my calcium level is 470 alk is 9.6 mag 1430 I'm ok with the alk where it's at but I want to lower my calcium to around 420 should I stop adding the calcium part and just add the alkalinity part until my calcium comes down ?? or should I add more 2 part? ive seen where people say just add the alk part until calcium comes down, then some say they add more 2 part and you should never dose one without the other in equal amounts so I'm a bit confused I think my levels are ok and in the range but I would like to lower the calcium I use reef crystals for waterchange about once a month at 1.026 and only about 5 gallons on a 90 gallon so it really dosent have much of an impact on my levels much any help would be great thanks

 

[Dan I]

Just let the calcium drop to your desired range. That is what I did and I am pretty sure the majority of other reefers have done the same.

 

[LEGACYLINE]

let it drop and still use the alk part right? thanks for the reply

 

[Randy Holmes-Farley Verified Community Expert]

Yes.

But I also highly doubt there will be any detectable difference between running your tank at 470 or 420 ppm calcium.

 

[Chuk]

I would leave the alk dose where it’s at and lower the Ca dose - not shut it off completely. If you shut it off you can go too far down and I’ve had trouble raising Ca before because it can start to precipitate out of you overdose on the way back up. Then you end up in this frustrating position with low Ca and it doesn’t seem like it will ever raise no matter what you do.

 

[LEGACYLINE]

thanks everyone for the info...randy I was under the impression that if calcium was 470-480 then my alk should be around 11-12 for that amount using the calculator so 9.0-9.6 alk is ok for higher calcium levels?

 

[Randy Holmes-Farley Verified Community Expert]

thanks everyone for the info...randy I was under the impression that if calcium was 470-480 then my alk should be around 11-12 for that amount using the calculator so 9.0-9.6 alk is ok for higher calcium levels?

IMO, the optimal values for alkalinity and calcium and magnesium are not related, but should be targeted independently.

As long as calcium is between about 400 and 550 ppm, I think there's little difference between the levels.

 

[PanchoG]

I would leave the alk dose where it’s at and lower the Ca dose - not shut it off completely. If you shut it off you can go too far down and I’ve had trouble raising Ca before because it can start to precipitate out of you overdose on the way back up. Then you end up in this frustrating position with low Ca and it doesn’t seem like it will ever raise no matter what you do.

+1

 

[madweazl]

thanks everyone for the info...randy I was under the impression that if calcium was 470-480 then my alk should be around 11-12 for that amount using the calculator so 9.0-9.6 alk is ok for higher calcium levels?

Since you're using Reef Crystals, keeping it in the 470 range should be easy to maintain (the salt mixes up in that range) with no reason to change it (wont change much if at all after you do a water change).

 

[Hans-Werner]

An Alkalinity of 9.6° KH is high and I would be worried more about this high alkalinity than about the calcium concentration. Alkalinity of natural seawater is just 6.5° KH. Corals will not tolerate alkalinity higher than 8° KH if phosphate concentrations are low.