Water pick up tube in fresh water tank...

[dstreight]

So, its my turn with bright green algae in my fresh water tank. I thought I had been keeping up with bleach on a frequent enough basis but obviously not.

Flushed it 6-times including using compressed air to try to dislodge contaminants from the bottom of the water pick up tube in the tank but its not having it. And had hyper-concentration of bleach-water mix the past 3-days in the tank.

I e-mailed Escape support/service but just to cover my basis', does anyone know what the bottom of the tube, in the fresh water tank, looks like? I tried using a hair remover for household drains but it stops short at the bottom of the vertical section of the tube; as if there is either a 90º elbow at the bottom (the portion inside the tank) or possibly a screen?

I'll probably have to remove the tank to repair this problem, but trying everything else first.

Thanks in advance if anyone can help.

[wackyburggeezer]

You might consider using Physan 20 to kill the algae. H2O2 is an alternative, but too hard on polymers that need to remain flexible. Give the Physan several days to work. ( works in my greenhouse).

[dstreight]

Thank you for the Physan 20 recommendation.

Ironically, or not I guess, I never had an issue with algae in the fresh water tank in 5-years of using the 15A, but this spring, instead of shocking it with bleach I used Purogene.

[dstreight]

Update: Ok, so I couldn't source Physan 20 before the last two camp trips with the 15A so I stopped by our local Camping World and got the Thedford 2-part cleaner & sanitizer to try to get the fresh water tank cleaned out of algae and other gunk.

Before using the 2-part system I didn't see the post about not using non-splash type bleach...yeah, still trying to get the last of the foam out of the system.

Long story short: I am not getting anymore bright green algae out of the tank but in its place are small sheets of gelatin like film that, apparently, is clogging the fresh water pick-up tube as the pump just runs continuously but never reaches full pressure. I can vouch for the semi-plugged pick-up tube as water flows through the inline filter/strainer sporadically.

Apart of draining & filling the tank more times than I can now remember I can see sheets of the film flowing around the opaque tank with the disturbed water apart of filling the tank.

I guess I'm going to need to drop the tank...and try to get it cleaned out properly. And, "while I'm in there", I want to spin weld a 1"NPTF fitting for the drain (in place of the OEM 1/2"NPT) for faster draining. And a 1-1/2" or 2" NPTF on the opposite vertical wall to aid in cleaning out the tank in the future if/when.

So, has anyone ever seen gunk like this in their fresh water tank?

[kathytony1985]

So, did the Thetford work to remove the algae? We had an issue this week with our water pump pumping, but not moving the water. Looked under the bed and saw green in the hose. Took off the water pump filter and it was completely clogged with algae. Cleaned it out. Cleaned the hose. Bleached the tank. Water pump is working now. We're going to keep an eye on it to see if the green algae returns. We are diligent about sanitizing too. Don't know why this happened after 3 years.

[Charliej]

I’m wondering if spray painting the tank black would prevent algae formation?

[dstreight]

Originally Posted by kathytony1985

So, did the Thetford work to remove the algae? We had an issue this week with our water pump pumping, but not moving the water. Looked under the bed and saw green in the hose. Took off the water pump filter and it was completely clogged with algae. Cleaned it out. Cleaned the hose. Bleached the tank. Water pump is working now. We're going to keep an eye on it to see if the green algae returns. We are diligent about sanitizing too. Don't know why this happened after 3 years.

I think the Thetford combo got rid of the algae as anything green is gone. But now I have the bio-slime to deal with (yes, I learned what is in the palm of my hand above is bio-slime). I've read several posts outside of our Escape forum, that state to use hydrogen peroxide (H2O2) at ~6% strength as, from what I've read, bleach won't dissolve bio-slime.

I just picked up 3-gallons of 12% H2O2 from Home Depot and was going to get it into the tank this afternoon but we're having a rare day here in Carson City: Its raining!

If this treatment doesn't do the job I'm just going to pull the tank and plan to add a 1-1/2" or 2" NPT port on the opposite side of the drain for access...or maybe a larger diameter port on top of the tank for better access yet and scrub-a-dubdub.

In 5-years of owning and using this 15A I've never had an issue with the fresh water tank (have shocked it with 1/4C household bleach at the beginning of each season). Something about this year...maybe it was the record # of days over 100º we experienced this past July.

[kathytony1985]

I would be interested to know if the H2O2 works. Keep us posted. Thanks!

[Ron in BC]

Originally Posted by Charliej

I’m wondering if spray painting the tank black would prevent algae formation?

It might prevent the formation of green algae but not other stuff. I've had boat tanks made from both aluminum and f.g. and both types are completely opaque.

The first time that I cut into the f.g. tank after it had been in use for about 5 years it made me queasy. All kinds of "stuff". Scrubbed it spotless and installed cleanout hatches large enough to allow me to reach into the tank. Still after a year or two they needed cleaning. So "stuff" grows both with light and without. Always wondered why tea made with that water didn't taste all that great.

Ron

[dstreight]

Originally Posted by kathytony1985

I would be interested to know if the H2O2 works. Keep us posted. Thanks!

$85 worth of H2O2 (3-gallons of 12% mixed at 50/50 with water to 6% concentration) and let it sit until today (4-days) and drained. The H2O2 still had carbonation/effervescence but if it dissolved any of the bio-slime it wasn't nearly enough.

After a couple drain & fills I could still see many "floaters" through the opaque tank sidewall when filling the tank. I then removed both the water pick-up side and the drain side fittings to get the largest ID for the respective fittings (1/2"NPT) and got about 1/2C of the gunk out. I used a sort of long pipe cleaner designed to remove hair from bathroom sinks from the top of the sink side and was able to pull more of the gunk out. If you've ever made sausage using natural casings...that's what it feels like.

So, I'm going to need to remove the tank, add a port/hatch to the top and see if I can get it scrubbed clean. There HAS to be a better/more efficient way to be able to scrub/purge the tank if/when it happens again.

I'm thinking it might be better, when the trailer sits parked for any length of time, to leave the tank as full as possible to eliminate air. Methinks that would help prevent mold/algae/bio-slime from growing.

[kathytony1985]

Oh, that's pretty disappointing. So, you think storing it full rather than empty is a better option to avoid algae and bioslime development?

[HABBERDABBER]

Back when I had a 15 year old Casita 16 footer, I added a deck plate hatch to the 11 gallon water tank for cleaning and drying it out. The water tank was under a dinette seat cabinet so it was accessible.

The deck plates come in various sizes, the plastic ones are ABS and there are stainless steel versions. They're O-ring sealed, most screw in the access cover but there are friction fit pop in/out style. I did mount my hatch on top of the tank, and never had a leakage issue. I likely sealed the flange with buytl tape sealant, but a good marine below the waterline caulk would work too.

A tank side mounted deck would likely work for access. I always drain my tank after every outing and even leave the drain petcock open. That is risky in some environments, but so far, for me, no issues.

Image of a deck plate hatch:

I doubt there is any benefit storing with a full tank or partial tank. Air isn't the growth medium, water is. A dry tank can't support much, if any biological growth.

[dstreight]

Freezing temps aside, I would think/guess, leaving the tank 100% full would help reduce the opportunity for mold/slime growth in a more/less air free environment.

I just sent an e-mail to Armstrong Nautical inquiring whether or not their deck plate would be compatible with a RV fresh water tank (from a thickness of material perspective for the water tank). https://armstrongnautical.com/pages/...at-deck-plates

I think I can set up the existing fill & vent tubes on the top of the tank along with the pick-up tube for the water pump, such that they are more easily disconnected (compared to OEM on my 15A) to allow quicker removal of the tank if/when proper clean out is needed again.

Always something to deal with it seems!

[dstreight]

I doubt, unless you purge the tank with warm/hot air for a long period of time, if you'd be able to get the interior of the tank completely dry.

If I had a larger capacity tank on the 15A where the lower portion of the tank hung down an inch or two more, from the bottom of the frame rail, a side clean out port would be advantageous. Take it to a manual car wash, use the high pressure sprayer to clean it out...

It would be nice to have 5-10 more gallons of water capacity

[HABBERDABBER]

Algae doesn't need air (oxygen) to survive. It PRODUCES oxygen, through photosynthesis.
Good luck with your full tank technique.
With a deck plate access, I was able to wipe dry the interior of the tank, and leave the deck plate open if I choose.

[dstreight]

Thanks HABBERDABBER, I appreciate your information as I'm out of my element when it comes to algae, mold, slime, etc., and these water tanks.

[Ron in BC]

Originally Posted by dstreight

I would think/guess, leaving the tank 100% full would help reduce the opportunity for mold/slime growth in a more/less air free environment.

Absolutely correct. After years and years with boat tanks with clean out hatches it's the underside of the tank top that have have the worse stuff on it. A partially filled tank creates the perfect growth environment. Air from the vent and 100% humidity.

If it didn't mean cutting a hole in my floor I'd have a clean out port installed in a flash.

Ron

[HABBERDABBER]

My experience is that the water tanks are not perfectly flat on any surface face, but bowed due to the flexible natural of the molded plastic and/or possibly the mold used to create the tank or the molding process.

You may fill until water is coming out the overfill outlet, but you're likely not 100% full. That implies a topside void space, with air, high humidity, and potential algae growth there, as Ron has seen in boat tanks.

It also seems nearly impossible to have the water tank perfectly level to eliminate any air pocket voids and completely fill it.

100% full? Not likely, I believe.

[Thane]

I had problems with cooties growing in my fresh water tank 8 years ago so I cleaned it out and now vacuum it dry after camping.

My 17b has a 20 gallon tank and 1.9 gallons is trapped after draining the tank. I think this shallow water on the bottom of the plastic tank lends itself to cooties growing.

I’ve since added a larger spin-on drain fitting to the bottom of the tank and use a home-made spray wand to further clean the inside of the tank. I check the inside with a borescope or mirror every so often. After vacuuming it out, I put a small piece of furnace filter over the open drain fitting for a few days to let it dry out completely while keeping bugs and dust out.

My previous posts are here. I know it will seem excessive to many, but my 16 year old tank is nice and clean and I like drying it out between long-separated camping trips; I look at as a game and it takes me less than 30 minutes.

https://www.escapeforum.org/forums/f...ance-7425.html

[HABBERDABBER]

Dry, dry, dry is better, or so it seems to me. A drain plug in the lowest spot of the bottom of the tank would work well. There's already the factory drain spigot attached, and mine doesn't leak. Another drain on the absolute bottom surface of the tank could help with tank sanitization.