Black Tank Question

I am in a habit of dumping the black tank every week. If I were to leave today I would drain my tank and when the flow stops I turn on the flush and close the valve for 5 minutes then let it drain for 5 minutes with the valve open and still flushing then close the valve and leave the flush on for one minute then turn off the flush then add chemicals thru the toilet. Drive to the next destination and leave as is for one week and repeat. Many years of doing this and tank has never given any problems.

I leave the grey tank always open until the afternoon before I move I then close the valve and when setup at new park I drain the grey.

I never look at my tank gauges.