Tank capacities

jonesj2

Well-known member
After reviewing the online specifications for our 2900MK, I see that the fresh water tank is 53 gallons, the grey is 80 gallons and the black is 40 gallons. So I take it the 2 grey tanks are 40 gallons each or is tank 1 and tank 2 different capacities since one is for the bathroom which more water would be collected and one for the kitchen which would not have as much water collected.
 

kurt999

Member
Our Sundance is 40 each.
It would help if they would have connected an overflow from the bath to kitchen.
The bath fills first.
 

jonesj2

Well-known member
That is the truth, we took showers over the weekend trying to be conservative and sure enough I had to drain some from the bathroom tank. Now the kitchen tank is only 1/2 full. An overflow would be great.
 

jbeletti

Well-known member
In practice, I drain my bathroom/shower Gray Tank about every 2 days - assuming we each take a shower a day.

Gray Tank 1 for my kitchen sink, I can go up to a week - just depends on usage.

Probably pretty similar to what you are experiencing.

There are RVIA standards and practices that govern RV plumbing systems. It is quite possible that they preclude tanks being plumbed together. Not sure.

What some people do is a manual equalization of the 2 gray tanks. I am not here to advocate the practice but I have read where some who are boondocking are able to extend their time between tank dumps by making sure the sewer discharge cap is on and secure, then pulling both gray tank valves. This allows the water in both tanks to equalize (in theory). I have never tried it and again, I am not advocating, just re-telling what I have read. Be sure to close those valves before traveling to the dump station and then drain the black tank first, followed by the grays as usual.

Jim
 

jpmorgan37

Well-known member
Buy one of these from Camping World and then you can open both gray tank valves which will allow them to equalize. Much better than having to make frequent trips with the Blue Boy.

John
 

grizzlygiant

Well-known member
Buy one of these from Camping World and then you can open both gray tank valves which will allow them to equalize. Much better than having to make frequent trips with the Blue Boy.

John

Why not just leave the cap on the sewer outlet and open both grey water valves at once. The tanks will equalize. Then close the valves, remove the sewer cap and catch the very small amount of water in a bucket and pour it back down the shower (or toss it on the lawn).
 

Jimmyt5

Well-known member
When I was at a Sunnybrook rally, someone asked the president why they were not hooked together and he said against the code, same reason that they didn't have a reversible Fantastic Fan, this would suck fumes from the tank vent that was close. He also recommended that you use a gate were the cap is.
 

jpmorgan37

Well-known member
Gary;

Many RV parks as well as municipal codes restrict the dumping of gray water. With the cap on and valves closed, the very small amount of water that you refer to is several gallons on my Landmark.

John
 

jonesj2

Well-known member
Thanks for all of the inputs, I was looking at the plumbing last night and equalizing could be an option in the future. I am going to try it at home with clean water to see how it works and how much will be spilled on the ground once it is complete.
 
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