So I’ve found out over the last couple years that pH is directly related to oxygen being replenished into the system. In my last house all my plumbing was in the stand with little to no circulation. The CO2 build up would constantly bring my pH down and I was constantly having to dose buffer. I even had to run a 20 ft airline from my Skimmer to outside my house to pull fresh air in constantly. My new house where my fish room leads directly to outside so the air, although insulated, is able to circulate much better now that I have 2 sumps. I was contemplating getting one large sump but decided to use what I had (RS100 and RS200) to make one continuous system. I’ve barely had to use any buffer since the move and with using two dumps at different levels, the water agitation is crazy so it helps me replenish the oxygen and stabilize myself pH