Next month im draining my tank and removing all of the water and gravel, which I will save, I have this running through a wet/dry sump. It will take two to three days from the time I drain the tank until I get it back, plus 1 day to get the water back to temp. How can can I save the bio filter, I will divert the return pump so its actully raining back down onto the bio media, so it will be a closed loop to keep the bio media wet while the tank is down. Will i need to add a couple drops of ammonia each day to keep the BB from dying? or can I just let it run in the loop for three or four days.
