Originally Posted by Benicia Tom
Went rving this weekend, light on black tank says 2/3 full tried to empty and only a little came out, before leaving used the tank cleaner and it seems that all that went in came out. Looked down toilet with flash light and can see water etc. about 5 inches from the toilet stop. Is this normal or is the toilet backed up?
In one word, yes it's normal. Tank level lights are highly unreliable as the sensors become fouled with waste and don't give reliable readings. Also, the tanks are slanted towards the outlet so you may see some waste that hasn't flowed all the way down to outlet.
I do as you did, looking down through the toilet with a flashlight and finding the true level. I won't dump tanks while parked until the waste is at the bottom of the toilet. However, I do dump right before travelling.