using an old RV freshwater water tank ok??

[purpdog5000]

Hi folks I am assembling materials for plumbing, and considering using an old used water holding tank I found in the planet fitness parking lot.. Yeah yeah laugh all you want, but I am on a budget and it seems like a good tank- 70 gallon white plastic tank, fits nicely under the bed, just wondering if anyone is familiar with the markings on the tank and could tell me what year it might be from?

Or if anyone knows the typical material used for these tanks and how much some time sitting outside would have compromised the integrity, or led to more microplastics being leached out?

my thought is that there are plenty of old plastic pipes in use in houses and in city drinking water systems that we all drink from, so what's the big deal with using an old tank so long as I clean it out with bleach, etc..

I am thinking I will incorporate some kind of endpoint water filter for drinking purposes before it leaves the sink tap.

Thanks all for input, and grateful for this awesome community

[desrtdog]

Tanks are typically HDPE (high density polyethylene), which is pretty resistant to chemicals and generally safe for drinking water. That said, prolonged us exposure can degrade the integrity. Consider whether you really want a used tank under your bed if there is a possibility that it’s integrity could be suspect…give it a good leak check!

Also, not knowing exactly what was in that tank before, I would tend to shy away from using it for potable water - maybe opting to use it as a gray tank.

[Cheezewhiz]

I'd give it a really solid inspection for cracks, warps, and most certainly smells.

Warping would probably mean heat exposure, which would mean possible brittleness. IRRC, HDPE is thermoforming, but if was uncontrolled..

If it checks out, I'd then wash it really good inside and out with soap and water, and check it again.

I'd personally pass on bleach, but would use a heavy dose of vinegar on the inside, followed up by homebrewer's sanitizer (or any of the food-safe let-dry sanitizers)

[Jolly Roger bus 223]

i do commercial HVAC and plumbing for a living.
i used old tanks for 2 buses now.
what i do to test tanks is to elevate them above where they are going to be in the bus and fill them with water.
the elevation is because water weighs 8 pounds per gallon in a back pack world in storage tank world you have to think of the elevated position if putting in the bus under a bed.
8 pounds per gallon at 70 gallons adds up.
when i chlorinate buildings i use swimming pool liquid chlorine of course over kill but havent failed a bacteria test yest on a military base that has and is being sued for bad water.
of course things have changed since then.
i still build new buildings for the govt and call BS when i can.
sorry went down the wrong road

[Jolly Roger bus 223]

just had a new post i lost? most likely my big hands.
ok short story whatever height your new to you tank is at is what i would test it as a minimum water weighs 8 pounds per gallon but trying to pump it requires 2.3 psi per foot of lift on a pumps used two repurposed tanks?
i manage commercial plumbing for a living and when it comes time for chlorination testing i go overkill with swimming pool shock.
i actualy like the liquid but it depens on job conditions.
you can call BS on me anytime you want ..
the psi of a water tower is 2.31psi of water pressure per foot above ground

[Jolly Roger bus 223]

if i didnt say it the water weight is 2.31 psi per foot above ground level so if your tank is in the bus at four foot

[AlphaHare]

El Monte was purchased by Elkhart in 2014.

B45.6 is a CSA spec for toilets and holding tanks. (But that could be just one of many uses.)

Z240.3.2 is a CSA spec for potable water in RVs.

So the tank was certified for both uses....

Welding around the ID plate sure looks a polyethylene (HDPE) tank.

Make really sure it was water being stored in that tank. I personally would not drink from a used tank for my potable water unless I knew exactly where it came from and how it was used.

[PNW_Steve]

I picked up a couple of used RV tanks to use in my bus. They were mad from ABS and turned out to be so brittle that I broke one when I dropped one end.

I junked them and bought brand new HDPE tanks.

I managed to find a pretty good buy on Ebay.

Good luck with yours.