Lowering PH

I have had the trend of my pH lowering recently and I am hoping someone might be able to help me out.

So since about June my pH has been fluctuating around 7.9 - 8.1 but has trended downward over time. In June I switched salt from Red sea coral pro to Seachem Reefsalt. Also at that time, of course it started to get warmer. The temp in my tank has been between 80-82 since June. Before June my pH was pretty constant at 8.4 and would rarely dip to 8.3 and my temp was always at 78-79. An additional problem I have been running into since June is that my alk is as unstable as hell. Prior it would sit at about 10-12 between WCs and I hardly ever dosed at all. Now if i don't dose it can go from 12 to 8 before my weekly WC without dosing. Yes there have been additions to sps and lps (only frags) and coralline has started to grow more as well but my freshly mixed Seachem salt has lower than 8 dkh, never exact, where as the Red Sea was always at 12dkh and I mix the salt in the bucket before i scoop it out each time.

I have been very unimpressed with the Seachem salt up to this point and will not be buying it again due to instability and cloudiness with prepared water after sitting for a couple hours, and sometimes immediately being cloudy and never clearing up until it is mixed in the tank for a couple hours.

I don't know if this is enough information for some theories or not so if you have any questions please ask because i would like to get to the root of this problem.

By the way, my mag and cal stay in good range 1400-1500 Mg and 450-500 Cal. Salinity is usually 1.026 until something stupid happens, my floor gets wet and it lowers for a couple days until i get it raised back up.

Thanks in advance!

 

Not sure what you are asking MD. I send clear to me, from what you say, that the salt is the problem. Alk will also affect pH.

 

Could your probe need calibrating?

Honestly, 7.9-8.1 us pretty typical. 8.4 seems a bit unusual.