I’ve owned my 1999 trailer for 8 years now. I start every spring with a flush out of the pink antifreeze in the plumbing, followed by a sanitation of the fresh tank and pipes with a quart of bleach mixed into the full 30 gallon tank. Last week when I went to service the system, I noticed my half inch diameter clear vent tube was clogged with dry yellow powder for the first 2 inches coming from the tank. I removed the hose and tapped the powder into a white coffee mug before washing out the tube and reinstalling. Could this be from filling up the tank in mountain areas with high mineral well water? Should I be concerned? I’m having trouble trying to attach a photo today

Thirty-two ounces of beach in a thirty gallon fresh waster tank exceeds every recommendation I’ve ever read. Quarter cup for every fifteen gallons is the standard IMO for sanitation. Looking forward to your pictures.

I'll second on the pollen.If you don't have a good water fill connection enclosed behind a hatch or door, everything that gets washed down the side of the trailer when it rains can get in the vent tube or the water fill port if it doesn't have a cap.I had my trailer in to a dealer to get the roof Corners resealed because the caulking was looking bad. While I had it there I also paid for them to wash and wax it. About a week after I got it back I found liquid wax that was sprayed on it in the fresh water fill hose. There was pink wax residue from the spray on wax that ran down the side of the trailer and gotten into the fresh water fill hose.The water fill port looked similar to the shorepower mouse hole with the same type of flap that snapped closed over the opening. I wasn't too happy about that one. I had to remove the fill hose between the outside hatch and the tank and scrub it out with a bottle brush and Dawn then reinstall the hose. I'm not sure if anything got into the tank but I flushed it a couple of times just in case.Within a month I replaced the cheap water fill port with a lockable hatch type after I found sediment that looked like dirt in the hose again after I had cleaned the wax out. I figured it was dust and dirt that rainwater had carried down the side of the trailer and it had weeped into the cheap water fill port.

mobeewan wrote:I'll second on the pollen.If you don't have a good water fill connection enclosed behind a hatch or door, everything that gets washed down the side of the trailer when it rains can get in the vent tube or the water fill port if it doesn't have a cap.I had my trailer in to a dealer to get the roof Corners resealed because the caulking was looking bad. While I had it there I also paid for them to wash and wax it. About a week after I got it back I found liquid wax that was sprayed on it in the fresh water fill hose. There was pink wax residue from the spray on wax that ran down the side of the trailer and gotten into the fresh water fill hose.The water fill port looked similar to the shorepower mouse hole with the same type of flap that snapped closed over the opening. I wasn't too happy about that one. I had to remove the fill hose between the outside hatch and the tank and scrub it out with a bottle brush and Dawn then reinstall the hose. I'm not sure if anything got into the tank but I flushed it a couple of times just in case.Within a month I replaced the cheap water fill port with a lockable hatch type after I found sediment that looked like dirt in the hose again after I had cleaned the wax out. I figured it was dust and dirt that rainwater had carried down the side of the trailer and it had weeped into the cheap water fill port.I've complained about those cheap city water ports a number of times on this forum, I'm glad that there is at least one other that understands the problem. I don't know how they get away with using this unsanitary junk. That vent will carry any thing down to the drinking water tank. I too, placed the port inside a locking hatch.Example

Yellow powder in fresh water tank vent tube | Good Sam Community

All_I_could_aff
Explorer
May 15, 2020
I forgot to take a picture when I was up there briefly this afternoon, but there is definitely a spot where I believe the tether strap at one point would have attached to the left side of the filler cap.

I may have to make some modifications to this area, but I find it odd that it took eight years of ownership for this yellow powder to become visibly noticeable and restrict the vent.

I reinstalled the perfectly clean vent tube today, so we will see if it happens again. Thanks to everyone for the help.
Lynnmor
Explorer
May 14, 2020
All I could afford wrote:
Lynnmor.... I do have an exposed fill cap and exposed vent screen like in the picture you linked to. But mine does not have the little cap tether strap, it just has a small 1/8!inch hole in the center. I used to assume that was to help venting, but after seeing your picture I’m thinking that the tether strap broke off mine sometime before I bought the trailer. I will be up by it probably tomorrow afternoon and I’ll get a picture.

My guess is that the tether is lost. What is the major concern is that screened hole where any rain, road spray, wash water, dust and whatever goes in and continues to your "fresh" water tank. The majority of RVs use this disgusting arrangement. I did away with the cheap thing and installed a locking hatch with the water fill and vents inside.
All_I_could_aff
Explorer
May 14, 2020
Lynnmor.... I do have an exposed fill cap and exposed vent screen like in the picture you linked to. But mine does not have the little cap tether strap, it just has a small 1/8!inch hole in the center. I used to assume that was to help venting, but after seeing your picture I’m thinking that the tether strap broke off mine sometime before I bought the trailer. I will be up by it probably tomorrow afternoon and I’ll get a picture.
Lynnmor
Explorer
May 13, 2020
All I could afford wrote:
So here are the pictures of what I shook out of the vent hose into a coffee mug
By the way, I had meant to say a cup of bleach mixed into my 30 gallon tank, not a quart, but that still sounds like double the recommended strength. Better than 8 times the recommendation though.

The yellow powder was all at the tank end of the 2 foot vent hose, right at the fitting that is molded into the tank itself.

Do you have the type of water fill/vent that I linked to earlier? If so, are you going to do something about the disgusting thing? Is there ever a yellow haze on surfaces near the trailer that might be pollen?
cptqueeg
Explorer II
May 13, 2020
Looks like mostly pollen and some dirt.
All_I_could_aff
Explorer
May 13, 2020
So here are the pictures of what I shook out of the vent hose into a coffee mug
By the way, I had meant to say a cup of bleach mixed into my 30 gallon tank, not a quart, but that still sounds like double the recommended strength. Better than 8 times the recommendation though.

The yellow powder was all at the tank end of the 2 foot vent hose, right at the fitting that is molded into the tank itself.
MrWizard
Moderator
May 12, 2020
Why the concern about the dump valve seals when sanitizing , do you drain the fresh bleach water through the gray tank ?
Mine goes out the drain valve on the fresh water tank and down the driveway to the gutter
Ride_S40T
Explorer
May 12, 2020
Not sure about the yellow, that's a lot of pollen. A lot.

For the sanitizing, any amount of bleach is not good for your dump seals. Believe the manual for my TT even says not to use it at all for cleaning sinks or toilets...oddly, it says to use bleach to sanitize but mentions nothing about dumping after the sanitizing process. We always do, though.
cptqueeg
Explorer II
May 12, 2020
Clorox says:

"To clean out a water tank, first thoroughly flush the tank using a bleach solution of 1 part Clorox® Regular Bleach2 per 150 parts water (a 500ppm bleach solution). I’m not sure of the size of your tank or how much bleach solution you will need, but here’s one example: if you want to make up 10 gallons of bleach solution, then you would start with 9 gallons + 15 cups of water, and then add 1 cup + 1 Tablespoon bleach. After flushing the tank with the 500ppm bleach solution, then rinse with a 10ppm bleach solution (1 teaspoon bleach per 10 gallons of water)."
naturist
Nomad
May 12, 2020
I, too, think it is likely pollen. And I absolutely agree that a quart of bleach for a 30 gallon tank is WAAAAY over to top. It will certainly burn the daylights out of anything in the tank. It also won't be kind to any rubber gaskets or seals in the system.

Forum Discussion

Yellow powder in fresh water tank vent tube

About RV Tips & Tricks

Related Content

White powder ??

Chili Powder

Can't find Calgon powder

Yellowing Skylight

Notorious Yellow Wire