Ph 6,7 - 7 Reef tank

[Matthatrick]

Hi

I am having a PH issue in my tank, it doesn’t go higher than 7.75.

calcium 450ppm
Mag 1350ppm
Alk 10

please see attached ore ammonia and heat.
I do have an outburst of red algae, but tank was like this even before it arrived.

I have a C02 scrubber installed already, my room is a bit stuffy but I leave all the windows open during the day

 

[Oliver d]

Re calibrate your Ph probe its not calibrated.check you ph with a marine ph test kit to make sure .

 

[Shawn.B]

double check your calibration, its very hard to get below 7.8 with carbonate based rock/sand in the tank

 

[Matthatrick]

thanks guys, did a normal test and its 8.2. I replaced the ph and nh slide and its reading fine now.