Mind boggled

[Poseidonspets]

If I'm running carrib sea Hawaiian black live substrate why is my ph 7.8 and alk low? I also use a purple coraline algae stimulator that is supposed to boost and stabilize levels and i don't have a protein skimmer. Im not using RO water and my tap water ph is 6.4ph. I condition it and use instant ocean reef crystals in a 32gallon with a powerhead and heater for a week before doing my water change and my salinity is 1.024ppm.

 

[CodyRVA]

What size is your system, how large and frequent are your water changes, how old is your system and what livestock do you have in the tank. Generally speaking the sand has almost nothing to do with this issue.

 

[Cory]

Sand doesnt provide alkalinity until the ph gets really low like 6 iirc

If your using tap water with ph 6.4 it may be lowering your alkalinity. You need to use ro/di

 

[Randy Holmes-Farley]

If I'm running carrib sea Hawaiian black live substrate why is my ph 7.8 and alk low? I also use a purple coraline algae stimulator that is supposed to boost and stabilize levels and i don't have a protein skimmer. Im not using RO water and my tap water ph is 6.4ph. I condition it and use instant ocean reef crystals in a 32gallon with a powerhead and heater for a week before doing my water change and my salinity is 1.024ppm.

There's no reason any substrate will have any significant impact on tank water alkalinity or pH.

Low alkalinity implies a need for alkalinity dosing.

pH 7.8 is fine, but low pH at that alkalinity implies excess CO2 in the water, probably from your home air.

 

[BlueCursor]

+1 on Co2 and home air. My pH varies by 0.3 as my home CO2 goes from 420 ppm to 810 ppm. I have a whole house air exchanger, so many people have CO2 levels above 1000 ppm.