Pressure Tank: Discolored Water

One month ago I installed an 86 gallon WellSaver pressure tank from Lowes in an unusual configuration: We are on a district water system, but it is unreliable, with the pressure dropping from a typical 60psi to zero (or even back-siphon) for 30 minutes or so every day or two. To prevent interrupted showers and so on, I installed a check valve and the tank (with a dielectric union) at the waterline entering our house.

In order to maximize our stored water capacity, I lowered the air pressure in the tank (when empty) to 15psi, about the minimum useable pressure.

It has worked great for the last month, but now we are starting to notice discolored (yellow) water.

- It doesn't seem like a nearly new tank should be rusting yet.

- I began to wonder if by lowering the air pressure to increase capacity I raised the water level above the level of the advertised "epoxy coating?"

- Also, the water probably remains stagnant in the tank much longer than a typical well installation.

- Or is there something in a new tank that just needs to be rinsed out?

Thanks for your thoughts.

Wow I can't imagine a water supplier could operate with 0 to negative pressure in any part of the system without breaking all kinds of health codes.

As far as the tank goes- I'd call the manufacturer and ask them.

It would be my guess that lowering the air pressure allowed your 60 psi system pressure to burst the bladder. Now the unpainted metel inside the tank is rusting and that would explain the discolored water.

No problem, I'm sure Lowes would be glad to give you another one.

bob...

Thanks for the comments. After draining the water (and air), it appears the bladder did rupture. And Lowe's did replace it . Interesting, lot's of warnings about not exceeding 100 psi, but nothing about lowering the air pressure.

This time around I have the air at 35 psi, sacrificing some volume; hope it lasts longer.

Southern Man: I believe it's just our under-sized lateral, not the whole system -- when the two neighbors ~40' below us (and the pressure reducing valve) take a shower at the same time, the old rusty 1" galvanized lateral can't supply the demand, and it draws from our house; or so I guess.

Then you need a double backflow prevention device, a fancy double check valve. And to force the water company to maintain the required minimum 40 psi water pressure to its customers, including you. And you should replace the galvanized line with 1" PE pipe.

Gary Slusser said:

Then you need a double backflow prevention device, a fancy double check valve. And to force the water company to maintain the required minimum 40 psi water pressure to its customers, including you. And you should replace the galvanized line with 1" PE pipe.

Click to expand...

I agree. Just be aware that if i'm not mistaken the double backflow valve will puke water on the floor.

Your back siphoning is evil and can contaminant the entire public water system. Get the water company out their ASAP and let them buy that valve because it runs as much as $600,

An RPZ pukes water on the floor, a double check does not.