Tank gunk -- help

[Zeppelinium]

Anyone know what this black stuff is and how to get rid of it? It's only on the top and sides (inside the tank).



I'm going to modify the tank with two 3/4" drains in the bottom. I can get the Metal Company in Denver to spin in the flush fittings.

BTW, when I was checking the tank for leaks I noticed that the vents are about 1" down from the top in the 5" tank. That means that if you fill the tank with the trailer level, you only get about 80% capacity. Depending on which side your kitchen is on (generally the tank fittings are on that side), you need to have that side of the trailer high, maybe 5 degrees, in order to fill the fresh tank to something like 95% capacity.

Zep

[eubank]

In an old geology class, we were taught to do a couple of tests after the initial visual: Sniff and taste. (Naturally, the teacher then explained that what we'd all sniffed and tasted was petrified dinosaur poo. I'm assuming that what you've got is something different.)

Lynn

[SteveH]

If I had to guess, I'd guess mold, and I know that's not what you wanted to hear. Clorox should kill it.

[Zeppelinium]

Originally Posted by SteveH

If I had to guess, I'd guess mold, and I know that's not what you wanted to hear. Clorox should kill it.

I'm only concerned about making the tank plastic brittle, I want to be careful about strong agents in the tank. If the Clorox is safe in this regard, I'm sure willing to use it--the smell will be gone pretty quick.

I'm willing to bet that most people have this stuff in their tank, but since they never look, they don't know it and it doesn't hurt them.

Zep

[TBRich]

I don't think you'll harm the tank if you don't leave it in full strength for too long. I'd position the tank so that the bleach hits the stuff directly and let it stand for a while, then fiinish filling the tank with fresh water so that the bleach gets diluted...and let that sit for a day at least. You'll need to rinse it several times to get rid of the bleach and taste, but that should kill whatever it is, and hopefully clean it...

For what it's worth ... I can see the top & sides of our fresh water tank (it's under the dinette), and it looks clean. We never drain it completely. Granted, ours is a relatively new AS, and we're the only ones who have used it ... but to help avoid this type of problem, whenever I fill our fresh water tank from an unfamiliar water source (in campgrounds, etc) I add a bit of a weak bleach solution...not enough to taste, but enough to help purify the water. We use our fresh water for cooking and drinking. So far so good ... and no bad taste.

[Aage]

Zep,
If bleach worries you, how about putting the tank back in your TT and taking a long drive down a bumpy road with a ton of crushed ice in the tank?

I'm with Steve, BTW. What could it be besides mould, or just plain dried poo?

[Melody Ranch]

Zep....last year, maybe two, someone mentioned the use of a powdered type chemical used in swimming pool cleaning and sterilization.....look for it and I will search around too.

[Aage]

Of course, there's always the GEO Method.

He is convinced that bleach doesn't hurt the tank, but the main things he leans on are a soap product and water softener. It makes a lot of sense, and members who have tried it in this thread seem very pleased with the results...

[CanoeStream]

Above-floor Argosy tanks receive plenty of light and can get that glorious aquarium green. I'd tend to do the following only with tanks removed (as yours are and my Argo tank was way back then). It took me a couple gallons of full strength bleach to finally get it cleaned out.

Bleach is a really strong scavenger of organic material (mold, algae, etc). 5.25% sodium hypochlorite as you buy it is stabilized. Add any amount of water and you have to use it within hours. Yes, the smell will be gone pretty quick. Not immediately -- but dilution + days + venting should take care of it.

[Wabbiteer]

Having uncovered a large wet bath-towel weight & size mat of algae in the Overlanders FW tank you have my condolences.

Even after letting the drain stay open for over a month that waiting surprise when I scooted back the tank locker floor AND 2/3rds of a tank of water that slammed half the tank down to the ground folding the plastic neatly at the molded partition scared me. The mat was evolving into consciousness and attempting to control its environment by plugging the drain line. Seeing the blob doubly decided that tank was history, and it fought back by promptly plugging the holes I drilled in the tank to drain it. The relief I felt tucking the tank into the "jaws of doom compactor" and being allowed to crush it by the trash truck hauler was worth whatever hassle waits in the future with FW tanks.

If'n I were you I would not hesitate to skip the sanitizers and move straight to muriatic acid (swimming pool acid) solution of hydrochloric acid. The plastics are immune but the sensor pickups might flinch at it so remove them if possible.

A very good sanitizer class is Bromines - hot tub sanitizers. This change from Chlorine based chemicals helps keep resistant organisms from blooming into city block sized mats scrunched into the plastic tank.

[Melody Ranch]

Canoestream got it.....Sodium hypochlorite - Wikipedia, the free encyclopedia
Thats what I was thinking of. Available inexpensively at pool supply houses.

[CanoeStream]

5.25% Sodium Hypochlorite in aqueous solution is commonly called bleach, Clorox, etc. Melody Ranch, is the pool stuff liquid?

Aha! From Wikipedia on the 'stabilized' point: "Household bleach and pool chlorinator solutions are typically stabilized by a significant concentration of lye (caustic soda, NaOH) as part of the manufacturing reaction. Skin contact will produce caustic irritation or burns due to defatting and saponification of skin oils and destruction of tissue. The slippery feel of bleach on skin is due to this process."

I do know that you can't dilute bleach and then store it. That defeats the stabilization. A bit off topic...

[webspinner]

Originally Posted by Aage

I'm with Steve, BTW. What could it be besides mould, or just plain dried poo?

Hopefully it isn't poo since this is a fresh water tank.

[Bruce B]

I would use bleach to clean the tank. One trick to get rid of the bleach taste is to fill the tank with a vinegar water solution afterwords. Let it sit for a day and all bleach taste is gone. The plastic tanks on our boat look like yours every spring! First bleach and then the vinegar and everything looks and tastes new again. By the way, have you wondered what the inside of all the fresh water lines look like? I'd treat everything...
Bruce

[Aage]

Originally Posted by webspinner

Hopefully it isn't poo since this is a fresh water tank.

Oh! Well, all bets are off.

Zep put the word "fresh" only down at the end of the post; my Sov is about the same age as his, and the black tank looks a lot like his fresh tank, however the ridge down the middle should have twigged me to the fact that it's the fresh tank.

No Geo plan for the fresh tank, IIRC. Even ice would be awkward to get in there.

[purman]

They do make a cleaning kit for fresh tanks you can pick up at an rv deal. They work pretty well. I used one on my old tank when we first got the AS.( lets just say it had growth, worst than yours) I ended up replacing the tank a few years later though.

[perryg114]

Bleach won't hurt the tank for short term exposure. It is probably HDPE. The suggestion of using warm water and vinegar is a good one after the bleach and is what I use to remove rubber taste from my Camel Bak water bladder. Using a milder solution of bleach say 10 ppm would be great for a yearly sterilize. You should be able to find out the ratio to produce 10ppm from household bleach somewhere online. I would use a couple gallons of bleach for your tank minimum. Pool shock is another alternative.

If you can get some strong hydrogen peroxide that will work great and won't leave a taste. Some folks on here use a peroxide mixture to clean their shower stalls.

Perry

[Frank's Trailer Works]

Zep, I would not recommend pool products. Pool products are meant to not degrade quickly. I think if used, you will end up smelling chlorine for a long time. Regular house hold bleach will do just fine for you. Throw in some ice and you should be able to use it to scour the film off. You could always buy a new tank and not worry about any of it. That is the route I have taken twice now in your very situation...