RO System Question

[grendel88]

I obtained an RO system from a friend and have attempted to get it going. After some troubleshooting, I found a bad valve and replaced it. Now, I hook it up to my water hose and get a constant drip of waste water and a slow (1 drip/second) feed from the "clean" side. I suspected my water would come slowly, but is this normal? Its a 75 gallon/day system. I have also bypassed the in line carbon filter because I could not figure out why the feed stopped. Is this an issue? Thanks

Jay

[Big_Pun]

i would replace all filters if they are not new, also to be sure your system is working properly, a water pressure gauge before the ro is a good idea. from the sounds of it seems like the filters are clogged.

[grendel88]

I replaced all the filters. Going into the 4th stage (RO membrane), pressure was good (I disconnected the hose at each junction to see if flow was ok). What comes out the other end is a slow trickle. The water pressure I have at my house is on the low side (older house). Could that have something to do with it?

[StevenSeas]

ya low pressure probably has something to do with it. You should get atleast 1 if not 2 pressure gauges to measure the in pressure and 1 for the out pressure on either side of the RO membrane. For mine i know it needs to be around 60 or so PSI. If yours isnt this high then you may need a booster pump

[Big_Pun]

exactly 60psi is perfect, but 40-50 can work but won't get full use of filters

[TXSea]

I thought that it was supposed to trickle on the "clean" end. I just got one too and put all new filters and membrane with new DI resin. It does the same. I've heard that you waste a lot of water to gain RO water. Mine is a steady flow out the drain end and trickle out the clean end. hmmmmmm.

[dipan]

Guys, a typical RO system has around an 8:1 brine to permeate ratio, that is an 8:1 waste to clean water ratio. You can easily just turn it on and see how much you are getting from each side. If your water pressure is pretty good, like 70-80 PSI, then you might be getting closer to 4:1. A trickle from the clean permeate line is not unusual.

I don't see what a pressure gauge after the RO membrane is going to do for you, BTW. You can certainly use one before it. If you really want to use two, put one before your first prefilter and then one just before your membrane. A drop in pressure across these can signal that they are getting clogged.

If you don't know how old your cartridges are then replacing them is prob a good place to start.

[grendel88]

Ok, thanks everyone. I remember the guy that inspected out house told us the water pressure was on the lower end since it is an older home. I plan to let the RO run for a day or so and see how much I get. Having a lot of brine makes sense.

[Big_Pun]

on a nice warm day i can get 5 gallons in 30-45 min at 60psi into my ro membrane.

[grendel88]

Thanks Pun, I'll keep that in mind.

[Big_Pun]

I use a 75gpd RO membrane

[TXSea]

It takes me about 2 hours to get 4 gallons of RO out of my 75 GPD system and that's from my kitchen faucet.