# Gray Tank Capacity



## rodgebone (Dec 28, 2019)

I recently bought a 2019/20 Outback Ultra Lite 291UBH. this unit has two gray tanks - one for the bathroom sink and shower and the other for the kitchen sink. Keystone lists the capacity of the gray water as 30 gallons but doesnt state how big each tank actually is. anyone know the size of these two tanks? im curious to know for treatment procedures and general logistical use


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## deepvee16 (Jan 27, 2014)

Congrats on the new trailer! Ditto "ob277rl" capacities.

I want to add this tidbit of information...

On our trailer, and likely yours, all three waste tanks exit through a common outlet. Each tank has its own valve. For us, our bathroom tank fills long before the kitchen tank. So, when we're at a site without sewer, I temporarily put a twist on valve. With the twist on valve closed, I open both grey valves so the tanks "share" with each other.

They're easy to find, but here's a link to show what I'm describing.

Good luck with the new rig.

Dave

https://www.rvupgradestore.com/3-WASTE-VALVE-WBAYONET-p/89-8304.htm


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## rodgebone (Dec 28, 2019)

my setup has a 60 gallon fresh tank, a 30 gallon black tank and two grey tanks (60 gallon total between the two)...2 dump outlets: a shared outlet for the black tank and the bathroom grey. the kitchen grey is on a separate outlet. all 3 tanks have their own individual blade valves. id prefer a common outlet for all three so im gonna get another short hose and a rhino tee to tie it all together to make dumping easier without switching the hose between the two outlets. still cant figure out how big these two grey tanks are - im guessing each is 30 gallon based on how long it takes to get full. i get about 2-3 showers out of the bath grey and about 2-3 loads of dishes outta the kitchen grey (i use a LOT of water to wash dishes lol). thanks for the info guys!


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## rodgebone (Dec 28, 2019)

i agree OB. the sensor light for my black tank isnt always accurate (a given) despite thorough flushing every time i dump. i found it most accurate to simply shut off the water and look straight down into the tank from the toilet with a flashlight. i can clearly see how full it is as the toilet dumps straight down into the tank.


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## thefulminator (Aug 8, 2007)

The easy way to test the capacity is to hook up to water and sewer, get a five gallon bucket and fill it from the tub spout pouring the water into the appropriate tank and checking the level reading after each five gallons. My 250RS 30 gallon grey and black tanks show full at about 23 and 25 gallons respectively.


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