RO water system

[sgt1577]

So I installed a Waterdrop RO system i our ‘20 Vacationer! No more carrying jugs of drinking water!

[K7JV]

Great!! We have what you did in our home kitchen. We also actually did a "whole coach" RO system in our last two motorhomes, and love it!!

BE CAREFUL - With your system, be sure you manage and/or provide for your discharge water. If your discharge is into your sink drain, that has the capability of filling your gray tank at the most inopportune times!!

With our whole coach RO, the discharge line is a ¼" PEX and it exits the coach, by itself, through a bottom opening in the wet bay. I can route the little black PEX line to the sewer connection, or adjacent grass, or a nearby shrub. But it does NOT go into the gray tank.

Assuming you've provided for that, you are going to LOVE your RO water in your coach!!!

[KenZ71]

What is typically the ratio of water discharge vs filtered water?

I'm considering a RO system as well but knowing there is significant discharge I'm hesitant. Maybe direct the filtered to Ice Maker and drinking. Discharge back to fresh tank for toilet flushing and washing?

[K7JV]

In our whole-coach RO system, we probably discharged between 55% and 60% of the water that came into the filter and membrane system. I think that is fairly normal.

I understand your interest in capturing the discharge. Like I implied above, I would NEVER consider routing it to any of my holding tanks. That said, you could probably route it to the fresh tank as you suggested, and that tank should overflow onto the ground under the coach if it reaches full. Note, too, that the water you would wind up with in your fresh tank would still be suitable for washing and showering. It just might get to be a bit mineral rich for drinking. But I'd absolutely avoid the gray or black tanks at all cost!

In our home, we use the RO from the under counter unit at three locations. One line goes to the small countertop tap that came with the unit, one goes to the under counter Insinkerator hot water dispenser with its countertop tap, and one goes to the refrigerator for the cold water dispenser and the ice maker. Love it!

In our Class C, we use it for everything, even including washing the outside of the coach from time to time. No drying or squeegeeing and no spots! Love it there, too!!

[Arch Hoagland]

I installed a reverse osmosis system in my house kitchen sink.

For every gallon of good water it produced there were 5 gallons of discharge water.

I routed that waste water outside to water my shrubs as we live in a severe drought area.

[sgt1577]

Thanks for the responses! Guess I didn’t realize how much water was going to be discharged 😜

I guess I’ll be rerouting that line!

[K7JV]

Wow, Arch, that's a lot of waste!

When we first put our RO in our coach, the RO to discharge ratio that we actually measured was on the order of 40 units of RO to 60 units of discharge, for about a 40% water efficiency.

In our home unit, there is a tiny hole in the countertop tap to vent the discharge line to atmospheric pressure, and you can peer in and actually see the discharge stream while it is producing. I've run the receiver empty several times to where the tap supply rate was reduced to essentially the RO production rate. While the production was down to just a trickle, it's hard to imagine that the discharge stream was five times that rate. But I've never measured it and timed it. I should do that!

Thank you for sharing what you found. I'm surprised!

[Terraboat]

Originally Posted by sgt1577

So I installed a Waterdrop RO system i our ‘20 Vacationer! No more carrying jugs of drinking water!

I'm wondering how much power the unit draws thru the inverter when you're not plugged into shore power?

Thanks,
Alan

[K7JV]

Zero electrical consumption, unless you choose to put in a boost pump on the inlet side of the membrane(s). We did that in our Dynasty, but I did not choose to do that in our Esteem. The boost pump increases the efficiency a bit, but it adds complexity as well as cost to the system. Note that having more than one membrane can significantly improve the water consumption efficiency.

[K7JV]

The RV Water Filter Store offered a neat package at the flea market in Yuma, years ago. The started with a Tupperware "tote" and punched a few well-placed holes in the walls of the tub for power and water lines. In the tote they had a manifold with three filter canisters (a 5 mil sediment filter, a 1 mil sediment filter, a carbon block filter) and two membranes mounted on it, a pressure switch and a boost pump.

Exiting the sides of the "tote" there were three water lines and one power cord. The power cord was for the pump. The pressure switch ensured that the pump would only run when incoming water pressure was present.

There was a hole for the hose from the park hose bib. There was a hole for the power cord. And there was a smaller hole for the ¼" PEX line to the coach for the fresh water fill and for the ¼" PEX line for the waste water discharge. Took maybe 5 minutes to "set up" and "tear down", and probably weighed less than 15 pounds.

It didn't take me long to find out how well I liked the system and the concept, and I installed the components into the rig and made it a permanent installation. The shower head, the bath and kitchen taps, and shower and toilet all truly still looked new when the coach was traded after 15 years of fun!!

[Rob_M]

Originally Posted by Terraboat

I'm wondering how much power the unit draws thru the inverter when you're not plugged into shore power?



Thanks,

Alan

Only what the house pump draws as it will cycle intermittently while it is doing a regen.

We have an RO system under the sink that only provides water for the little drinking water spigot and ice maker, so discharge isn’t a terrible amount. It’s never caused our gray tank to over fill.

We have two large 5 and 0.5 micron filters in the wet bay that catch the big stuff coming in.

[sgt1577]

Originally Posted by Rob_M

Only what the house pump draws as it will cycle intermittently while it is doing a regen.

We have an RO system under the sink that only provides water for the little drinking water spigot and ice maker, so discharge isn’t a terrible amount. It’s never caused our gray tank to over fill.

We have two large 5 and 0.5 micron filters in the wet bay that catch the big stuff coming in.

Mine is hooked up the same. Just the little spigot and the ice maker. I’ll give it a try and see how it goes

[TXiceman]

I worry with all of the people so worried about water quality when most of the water supplied in the US is safe for drinking and the water wasted on RO systems. A true RO system will reject about 1 gallon of wastewater for each 2 gallons of purified water. I know this does not sound like much, but you start adding this up by thousands of people and that is a lot of reject water. With most of the western US experiencing drought and record low water levels, water is becoming a scarce commodity. We need to be finding ways to conserve water rather than be putting it down the drain or on the ground.

Ken

[Old-Biscuit]

Originally Posted by sgt1577

Thanks for the responses! Guess I didn’t realize how much water was going to be discharged 😜

I guess I’ll be rerouting that line!

Check the specs on your model
From your picture it looks like you have a 'G2' model
That has a 1:1 ratio........1 gallon pure to 1 gallon waste
400 GPD

If it is the 'G2P' model
That has a 2:1 ratio........2 gallon pure to 1 gallon waste
600 GPD


Different models/versions/purity results in various pure to waste ratios
*cleaner the water the higher the waste ratio