Grey water tanks - equalize?

[govslug]

I read somewhere on here where you could open the valves between the two Grey water tanks to equalize the tanks. The shower tank is about full, I did this and let it sit for a full day. Nothing moved. I even think that what little was in the kitchen just filled the main line. Kitchen went from 1/3 to zero.... Shower stayed at 2/3. What's going on.

[1retired06]

Not sure I understand re equalizing tanks. If you are saying you opened the gray tank for the shower and nothing dumped, I would first consider that the valve is not opening, or opening part way and blocked. And despite your unit being new, may be getting false readings on the gauges.

[govslug]

I was thinking the fuller tank would drain into the emptier tank so we could have more room for shower water. Tanks drained when emptied last trip which was our first with this camper. I know gages are not very accurate or dependable. We just fill the Fwd. Tank a lot sooner than the galley due to showers.

[jimcol]

They will only equalize if the two tanks are installed level. Not familiar with your model but I believe the galley tank is higher than the other gray water tank. (or vice versa) Think it becomes an issue if you have the drop frame. See Carl & Susans remarks in this thread: http://www.montanaowners.com/forums/...ualize+gray%2A

[govslug]

Thank you, I believe that is the reason. I was starting to think there were check valves in the line, but have not heard of those in any camper.

[Butch & Kathy]

On my 3160RL I can open both grey tanks and get them to share the capacity. Make sure to install another waste valve on the drain line.

[psomers]

If the shower tank is the fuller tank, then yes if you have a termination valve you can drain shower to galley but not other way around. The shower tank is a good bit higher than galley tank.
I just replaced all three valves and noticed that to be true.

[govslug]

I have a 305RL....looks like the galley tank is higher. The shower tank sits down with the black water in the drop frame area. It definitely didn't equalize when I left them both open. And I do have a valve at the end.. Have had a previous rv and know all to well about taking the cap off.

[mhs4771]

I know I can't equalize my Grays because the Shower/Washer Gray is in the Drop Frame section with the Black, my Galley sits in the main belly above the axles. So the only thing I could do would be to fill an empty Shower/Washer with the Galley, but as you know, Shower/Washer Gray generally fills much faster than the Galley.

[Mudchief]

With the older units you could do that because everything was on the same level. With the new dropped frame units the tanks are at different levels.

[psomers]

You know I was wrong. The galley tank is higher than the shower tank. When I was looking at them I was on my back looking up. I'm easily confused.

[rohrmann]

Beware leaving the tanks that full too often, especially with the ABS tanks. I had to repair a crack in the bottom of our grey tank last year where the flexing of the bottom of the tank ultimately caused a crack in one of the molded ribs. I was able to fix it with a Plastimend kit. I added a couple extra braces across the frame below the tanks, and installed blocking between the braces and the bottom of the tanks. They don't flex now and I don't worry about ocassionally having water back up into the shower. This also keeps the same thing from happening with our black tank.