I should have figured this out by now but I am still baffled when it comes to pH.  I try to maintain my tanks between 8.0 and 8.2, sometimes it drops to 7.95ish but since I only keep fish and softies I'm not real worried so long as it stays fairly constant.  I tried the reverse light cycle on my refugium and to be honest I didn't much difference in the pH swings with or without the reverse light cycle (both vary about the same).  Anyway, what baffles me is my RO/DI top off and salt mixes.   I keep a 55G of RO/DI full with a small powerhead circulating and I mix Reef Crystals in another 45G Brute to use for water changes.  I mix the salt and keep it circualting with a Quiet one pump.  I add enough pH Buffer (Seachem Marine Buffer)  to raise the pH to 8.2-8.3 (checked with my RKE and a seperate pinpoint).  After about 48 hours if I test the pH again it drops significantly down 7.8 or 7.9, I don't understand why??  Usually without the pH buffer the salt mixes at about 8.1 or less.  I used to add reef Builder to the mixing container as well but haven't done that in a while. There is nothing in the mixing container and I clean it out every couple of weeks.  I can't figure out what is going on.  Any ideas?
signed,
Dazed and Confused in Marietta :confused2:
				
			signed,
Dazed and Confused in Marietta :confused2:
 
	 
 
		 
 
		 
 
		 
 
		