+1 for all the above.

FWIW my planted tanks including those with peat moss in the substrate all have a pH of 8.4-8.8 with the api high range test kit.

The reason is simple. Live plants consume the carbon dioxide so the tank is a net consumer of carbon dioxide and producer of oxygen each 24 hour period.

removing carbon dioxide and hardly be stressful for the fish and in fact lowering the pH adds carbon dioxide which is why you may be seeing some stress.

Oh I have neon tetras, glow fish, silver hatchetfish, in addition to plattys and guppies. In the past angelfish also. So it is not just some super hardy fish that can tollerate high pH. Even the soft water lower pH fish thrive in that environment.


my .02

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fw leiden since 1979, fo salt since 1979, mixed reef 55g 2002-2009. Strong emphasis on the tank taking care of itself. Balanced with plant life, no water changes, tap water, no filters in FW. Only dosing calcium, alk, mag in marine reef tanks. http://www.aquariumforum.com/f15/my-...ods-26410.html
recent tanks (till 2009) 7 years- 10g FW leiden 7 yrs, 55g mixed reef 7, 2 yrs, 20g FW leiden, 10 g fw leiden , 29g mixed reef, current tank 55g leiden