pymmint wrote:
NOT so much having to “pull” two handles, BUT to NOT have the grey tank filled up so fast that I have to dump more often; I can add dish water & “run off” shower water, but that also runs the risk of the water sloshing into the composting/ solid waste side.
You have me confused. What I read is that you now have three chambers. The composting toilet has one. The composting urine bypass runs to the second/black tank and grey water runs into the third/grey tank. Does the urine bypass have a check valve to prevent back flow from the black tank?
Does your MH have a combined exit valve like this?
If so, others above have explained simple method of adding the Valterra (one brand) gate valve (like below) to combine and control the dump.