Hi
I have a theory on my low ph.
Could it be caused by my well water having high amount of CO2?
I have read that with well water high CO2 will cause di resin to be used quicker and that would be my rodi system I have used my DI resin faster.
If it is high CO2 could running an air stone in my rodi water for water changes help?
I did notice from the graphs on my apex that Sunday nights after a water change Sunday morning is when it bottoms out. Last week by Wednesday it was up to 7.95 tonight down to 7.5.
What do you think?
Joe
I believe the pH of RODI water should be 7. As it's exposed to the air, it will find an equilibrium with concentration in that air.
When you 1st mix your ASW, it should hit a pH targeted by the salt manufacturer. Most look to hit a pH of 8.3ish. As that gets exposed to the air, it will also find an equilibrium. Since house air is usually higher in CO2, the pH of ASW will naturally drop. If you aerated it will higher CO2 house air, it will find that equilibrium faster.
Your overnight drop seems quite high to me. Options:
1. Refugium on reverse lighting schedule
2. High-ph Alk dosing at night
3. CO2 scrubber with Skimmer