RO/DI Always leave on?

TragicDog · Sep 25, 2020

Hi hive mind, I've got a 75GPD RO/DI. waste line is run into the washing machine drain. it's attached directly to the cold water line with a it's own valve, and I have another valve on the output line at the end which currently hangs loose in my garage.

What I'm wondering is can I leave the valve feeding the unit on full time? if no water leaves the clean water line does water still run out the waste water line? What's the detriment to leaving the feed valve on?

highest_tides · Sep 25, 2020

You want have waste constantly coming out and can leave the pressuretechnically, but I like to flush the system every time personally.

HeyJay · Sep 25, 2020

The waste water will need a check valve to also stop, but some RODI units have one already

KStatefan · Sep 25, 2020

If it does not have an auto shut off valve water will still flow thru the waste line when the output is shut off.

highest_tides · Sep 25, 2020

My fault i misread the post. I have a valve on my intake line

TragicDog · Sep 25, 2020

HeyJay said:
The waste water will need a check valve to also stop, but some RODI units have one already

How do you know if it has an auto off on the wast line?

and if it doesn't what's the easiest way to add it?

Bfragale · Sep 25, 2020

I believe this is what your looking for:

1/4" Auto Shut Off Valve

Installation Instructions 1/4" Automatic shut off valves are used with float valves or pressurized tanks to shut off an RO system. It utilizes the back pressure created by the float valve or pressurized tank to shut off the water supply to the membrane. Without an automatic shut off valve...

www.bulkreefsupply.com

If you have one you should be good to go. If not $10.
Good luck and happy reefing!

TragicDog · Sep 28, 2020

Bfragale said:
I believe this is what your looking for:

1/4" Auto Shut Off Valve

Installation Instructions 1/4" Automatic shut off valves are used with float valves or pressurized tanks to shut off an RO system. It utilizes the back pressure created by the float valve or pressurized tank to shut off the water supply to the membrane. Without an automatic shut off valve...

www.bulkreefsupply.com

If you have one you should be good to go. If not $10.
Good luck and happy reefing!

perfect, thank you so much.

Chuk · Sep 28, 2020

That’s supposed to go between the DI water and the inlet, not the reject line. That way it shuts off the whole RO unit when your DI is full not just the reject line.

TragicDog · Sep 28, 2020

Chuk said:
That’s supposed to go between the DI water and the inlet, not the reject line. That way it shuts off the whole RO unit when your DI is full not just the reject line.

so it won't work for what I need? or If my off valve is before my DI it would? easy enough to move a valve.

Chuk · Sep 28, 2020

It will work, its meant to shut off the whole RO system for you.
One side goes on the DI line and the other on the feed water. When you shut off your DI on the far end the pressure builds up and then pushes the diaphragm in that valve shut on the inlet to your unit, the whole inlet gets turned off so you don’t have water running to drain all the time.