Grey tank bypass

[Jeff Bittner]

2021 International 25FBT. After 3yrs we've noticed after 2-3 days when we're ready to shower that the black tank is about 30% full but the grey tank is too full for 2 showers. I've read that on some models the bathroom sink drains to the black tank. Why couldn't AS or someone design a bypass so shower water could be diverted to black tank if desired? This would save on some dumping. Thoughts?

[ITSNO60]

Well if the gray backs up into the shower you are standing in gray water, not a huge deal but if the black backs up into the shower......
I have also pondered a solution and since my gray (motorhome) has a macerator pump my thought was to put a tee with a one way valve in the macerator line and pump some of it into the black tank when desired, so maybe you could rig up a pump?
Something like this would need to be closely attended to and monitored by a qualified user so I doubt you'll find a commercially available option.

[Jeff Bittner]

That's a good idea. Thanks.

[Bunker]

In a pinch, we use a bucket in the shower and try to catch as much water as possible so we can dump it in the black. We might even use the same bucket to wash dishes in and dump in the black. We might even dump the grey…but that’s a different question.