yeah thats a good point, i did think of that earlier. my water is around 7.2 pH and slightly hard
I'm 7.6 and no longer keep geos, most people don't realize how well their fish aren't doing in harder water, I know I didn't. When I switched to RO, I saw better color and growth in 3-4 months than I did in over a year prior. I would add some crushed coral or coral based substrate and go the front route if I were you. Just a suggestion though.