PH Spike after dosing calcium carbonate

[atp0726]

What is the acceptable range for PH to spike after dosing calcium carbonate? I am currently dosing BRS 2 part solution and when I add the calcium carbonate each night at the same time I get an increase in PH usually .2 - .3 which lasts for a couple hours before coming back down within .1 higher than the ph level prior to the dosing. Is this swing placing stress on mainly SPS corals? I intend to get dosing pumps which I know will correct this however, I will be adding it daily for a little while.

Also, I add the calcium carbonate to the sump in the same compartment as the probe which I expect to show a much higher false reading initially but not lasting more than 2 hours before it comes back down.

 

[jerpa]

Calcium chloride is the calcium half of BRS 2-part. It should not raise the PH. The alkalinity portion(sodium carbonate) will spike your PH. The jumps you are describing would be concerning. How much are you dosing per evening? Splitting the dose may alleviate the problem. If it continues to be an issue you could switch to Recipe 2. Sodium bicarbonate(baking soda) won't have this effect.

 

[disc1]

The calcium part is calcium chloride not carbonate. Calcium carbonate is what your sand and rocks are made of and it will not dissolve at all in seawater.

+1 to using a bicarbonate recipe if you want your 2-part to leave the pH alone.