i know i will prolly get told off for this but i while back i got sick of always playing with my water to keep it at what is concidered optimum quality so i started changing things, i did not do water changes as often and i slowly let the ph rise to a lvl that was concidered death for some of my tank inhabitants, to my suprise they did not seem to mind one little bit, the would breed and carry on as usual, mind this was done over a prolonged time frame so they could adjust ...in addition i cut right back on cleaning my filters and so on because in my opinion bacteria is awesome in your filters, i almost never touched the media for my marine tanks as well and when i did clean or change somthing it was only one thing at a time...
After much playing arround i have come to believe that many water changes , filter cleaning and having a PH at one end of the sclae or the other does not have to make a difference at all, it appeared to me as tho it was the other factors that seemed most important.
The only exeption to this i found was with corals, they do not tolerate a hell of alot in my opinion, but then again maybe it is just me.
What i would do is just slowly adjust your fish to a higher and higher PH until the time that you do not need to add anything to your water