Planted Tank Enthusiast
Join Date: May 2003
Location: Blackwood South Australia
No 6.4 is fine for tetras, I have tetras in my tank and they are fine at the PH.
You wont need to raise the CO2 level even with your compacts, the plants will use more CO2 but if you maintain this level with a controller then you won't need to jake up the CO2.
Eheim Pimp Club member #3: Scribe to the Eheim Pimp Club
90 gallon, CO2 dupla injection, Dupla substrate heating, Dupla Laterite with iron stone substrate, Aquastarlight future 3 x 150 metal Halides, Eheim 2026 pro2's and heavily planted with Discus