Gray water tank open or closed?

[Corey]

I have a 2018 3921GK Redwood fifth wheel.. It has two gray water tanks that I normally leave open year round. I keep the black tank valve closed until full then I dump it. I've heard both; keep the gray water tanks closed and open.. Anybody have the correct answer to this??? And of course, the sensors in all three tanks don't read right. I can never seem to keep them clean. My gray water tank 1 reads full, gray water tank 2 reads 1/3 full and my black tank reads 2/3's full.... Any suggestions would be greatly appreciated..

[mhs4771]

Might depend on where you're camping, but I was leaving my Grays open during the winter in Florida and I ended up with a good size Cockroach living in my washer until I finally was quicker than him. So I have to assume he came in via the Gray line and then had no way to get out of the washer other than the soap/rinse compartment as he would be there when I opened to add soap.
Now all my tanks remain closed except when draining.
That's my Story and I'm sticking to it!!

[travelin' texans]

I left the bath grey valve open when connected to sewer otherwise with showers & washing laundry I'd be draining every other day.
I always left a sag in the sewer hose where it connected to the rv then put the rest of the hose on the support, this made a p trap in the hose to prevent gasses & critters from entering the tanks.

[XCMARK]

I let my gray water get 3/4 full so i can use the gray water to flush out the the hose after dumping the black water.

[Trailer1234]

I leave open for 6 days. Close for 1 day and use to flush black line once a week for the two of us. Am on our 5th RV and empty/full monitors never work.