coolmom42 wrote:
Best thing to do is not put the chemicals in the RV tank to start with.
Use plenty of water, keep the vent open, keep your air admittance valves for the sink drains working correctly, and don't flush with the fan on. Do this and you shouldn't get any odor in the RV.
X2. Since the black tank is just a "holding tank", and not a septic system, we were told no chemicals are needed. We have never used any and have never had any odors. It has to be emptied pretty frequently so I don't see why it would need chemicals anyway.