Thor Forums

[gmc]

As several had said - liquid makes all the difference...
Just reading the frequency of your issue (every 3 days) - are you leaving the black tank valve open while hooked to sewer?
Only way I can picture the problem you are having at that frequency...

The BLACK valve should be CLOSED normally - water in the tank to start with, add your choice of chemicals/additives... and use it... (more use = more liquid and more time for chemicals/additives to do their thing...)

I typically leave the GRAY valve OPEN until a day or so before I dump the black - closing it then and allowing it to collect some water.
Dump the black... use tank rinser if you have one... dump the gray to rinse the hose... and start over (more water... chemicals/additive... etc)