Ro pressure tank as auto topoff??

I have no running water source to my tank. My ro unit Is on the other side of the house. So I was wondering if I put a 5-10 gallon ro pressure tank next to my tank and ran a float valve in my tank then I could fill up the tank every week and not worry about over flow becaus my sump can hold well over 15 gallons of over flow. Can a ro tank hold or/di water?

 

It's easier to just run a 5 gal pail with a snap-on lid with a small pump inside. Connect the pump to the float valve, and away you go.

We use 1/4" poly tubing (the same as used for the RO/DI unit) and a John Guest adapter that screws onto the outflow of the pump. I added a T above the waterline of the pail as a siphon break since the end of the ATO supply line is submerged in the pump bay of the sump.

 

The problem with the pressure tank is the bladder will leach nasties into RODI, and the bladder will eventually fail from this as well. They're designed only for RO water, not RODI.

 

It is not advised, RO/DI is extremely agressive, trying to get back to its natural "dirty" state, so will leach things out of the bladder and attack the metal of the tank. Store RO/DI in something safe like a Rubbermaid container, plastic drinking water jug or glass aquarium with a lid.