The tank I was referring to is Brad's (aka
@Reefnjunkie ). Maybe he can chime in himself, but on our local forum I remember him talking about running his 400 gallon tank towards 7.6-1.8 range. I think we can all agree that his tank is something to strive after. Maybe's he's changed things, but he'll have to say.
It's not that I run my tank at those levels (7.6-7.9) that's just where it ends up. I've not read all 7 of the pages but what I've skimmed is what a lot of us have either heard, read, or done. Years ago I've tried every suggestion posted and the CO2 scrubber was the most effective and the highest cost to maintain.
My tank is consistently in the 7.65 range at night (winter time) and as high as 7.95 in the day. The same is basically true for summer because I have the doors closed for the A/C. There are times when I open the doors and can hit 8.2 even 8.3 wooo hooo LOL
In my experience it's not worth the time or effort or money (unless your board, like to tinker with the tank (like we all do but...) or have copious amounts of money) trying to keep a tank in the 8.3 range. If you have to have that number, ditch the calcium reactor and switch to dosing - that's not a real suggestion, never change to dosing from a calcium reactor
Honestly I have NEVER worried about PH. From what I understand corals grow extremely slow in lower PH. Maybe I am mistaken. I would rather not take action and not worry about PH. Can you link me to some of these lower PH sps dominant tanks?
I evolved into the "never" worry part about PH and quite chasing magical numbers years ago. Not sure about the extreme slow growth of lower PH or how low the low is but my acros grow fast, some faster than I wish.
I'll count my recent set back as a blessing since it allowed me to trim all but one of those large colonies in my display but that's a whole other thread hahaha.
Rev the link to my lower SPS dominant tank can be found...... well, you know where
Good luck OP with whichever direction you go or do