PH drop with Reef Crystals

[Panicked Reefer]

Has anyone else noticed a drop in ph when doing a WC? I noticed it with fritz but it is more of a drop with reef crystals. I suspect it's what they use for alk. Just curious if it's a known side effect or not.

 

[Randy Holmes-Farley Verified Community Expert]

Has anyone else noticed a drop in ph when doing a WC? I noticed it with fritz but it is more of a drop with reef crystals. I suspect it's what they use for alk. Just curious if it's a known side effect or not.

pH on water changes will be a combination of the pH of the new water and the old water. Assuming both are seawater of similar salinity, the value will fall in betweeen them.

if you are getting a drop, that is because the new salt water has a lower pH, and that lower pH with RC (a high alk mix) is caused by mixing and aeration with higher CO2 air.