Converting my 20g into a microfish/ cherry shrimp tank. Two of my new species to this tank are best in water with a very low ph. Licorice gouramis and green neon tetras. My current ph is around 7.5. Have a few pieces of driftwood but that is only having negligible effect. So was thinking about adding peat moss to the filter. Is that a good idea? I understand that it will stain my water. Other fish in tank are celestial pearl danios. Pygmy Cory's and cherry shrimp. Those all should be fine if lowered to about. 6.5