The ph does need to be buffered and raised. You should have been adding the buffer to the mix or to the FW while you were bringing it down. Do not add buffer directly to the tank. If need be, pull out some water. If all readings are ideal, which they are not, mix the buffer with the water from the tank in a separate bucket. My immediate concern is the 2 nitrite! The 20 nitrate is nothing to smile about either. Was this qt cycled? Get some water mixing now for water changes. ALWAYS check the ph before you add water to the tank. Never add buffer directly to the tank. When you are doing top offs, check the ph before hand. If the ph of your RO water is low then buffer it 24 hours before it goes into the tank. Have some Ro buffered water ready for top offs.
