RO beginners guide somewhere?

[afqu]

Is there anywhere on the net that has a "good" descriptive beginners guide to RO?

I read about boosters, in line pressure gauges, regulators for the different sizes of membranes, but nowhere am I finding how much pressure they need to push the water thru them, for what size membrane (GPD), how this all works and how a regulator is needed/used in conjunction with the membrane size etc.

I have well water and my pressure is 42 at the holding tank. I have an RO that is either 50 or 100 GPD. Was given to me (new) with no marking on the parts. Plain box says 50GPD and was crossed off and 100 hand-written over that. I bought a membrane for a 50 (plus sediment and carbon) and hooked it all up. I can get my water right at my well's holding tank.........42 lbs of pressure.

I ran the RO tubing to the outside of the house to flush. I fill a gallon jug with waste water in the same amount of time as I get 1/4 cup of good water . That is not 4:1 no matter how you do the math. That is assuming the 4:1 means bad:good water, and not the TDS numbers I am reading about. I really don't have a clue.

So I assume I need a regulator for the 50GPD, and perhaps a booster for pressure?

I so didn't want to come here, and ask the same old questions, but have searched high and low to no avail. Someone please help!
Jean

[Victor1046]

I found this very helpful!

http://www.melevsreef.com/ro_di.html

[kau_cinta_ku]

60 - 70 psi of pressure is best for your membrane. lower pressure will produce smaller ammounts of water and could damage the membrane

[afqu]

Thanks for the input from both of you. I am beginning to undestand a bit better..

So, what I am reading is.......if I can get 60 or so lbs of pressure going in (need booster obviously) all I need to do then is get a valve in my waste water hose and adjust it until I get my 4:1? Or is that too simple?
Jean

[Nanz]

If your using Well water you might want to include a UV in your RO setup since your well water will have more microorganisms in it than normal tap water. Tap water is dosed with Chlorine usually a trihalomethane known as Chloroform.. Cl3-CH.

[PJSEA]

What do you have on the oulet (wastewater line). There should be an orifice/restriction in the line somewhere. You may be able to buy an orificed valve or try the valve like you were considering.

I've always run mine on "city" water systems which only give around 50 or so psi to my 75gpd RO unit. I still get 75 gpd even though higher pressure is recommended.

[BuckeyeFS]

Let me provide this link to a ReefCentral RODI FAQ, and then I'll answer your questions: http://reefcentral.com/modules.php?s...showpage&pid=2

...but nowhere am I finding how much pressure they need to push the water thru them, for what size membrane (GPD), how this all works and how a regulator is needed/used in conjunction with the membrane size etc.

The membrane manufacturers rate their membranes at a given pressure and temperature, as well as some other standard conditions. Filmtec brand membranes use 50 psi as theri standard, other manufacturers use 60 or 65 psi. You can have less pressure, but you won't be happy if you have less than 40 psi, in our experience.

When you refer to a regulator - do you really mean a "flow restrictor?" they are two different things.

I have well water and my pressure is 42 at the holding tank. I have an RO that is either 50 or 100 GPD. Was given to me (new) with no marking on the parts. Plain box says 50GPD and was crossed off and 100 hand-written over that. I bought a membrane for a 50 (plus sediment and carbon) and hooked it all up. I can get my water right at my well's holding tank.........42 lbs of pressure.

We need to make sure your flow restrictor is matched to the capacity of your membrane. Can you see/identify your flow restrictor? If yes - do you see any numbers on it?

I ran the RO tubing to the outside of the house to flush. I fill a gallon jug with waste water in the same amount of time as I get 1/4 cup of good water . That is not 4:1 no matter how you do the math. That is assuming the 4:1 means bad:good water, and not the TDS numbers I am reading about. I really don't have a clue.[/quote]

The ratio you are wanting is about 4 parts waste water to 1 part purified water. Now you are at 64:1, or 16 cups : 0.25 cups. Me thinks you have the wrong flow restrictor installed.

So I assume I need a regulator for the 50GPD, and perhaps a booster for pressure?

Let's start with getting the correct flow restrictor - that will change the pressure you see on the gauge of your RO system. If it is still to low, then we can think about a booster pump.

Flow restrictors are only a few bucks, and will take just a minute or two to replace.

Russ

[afqu]

Thanks guys/gals for the advice. I had water tested many years ago when I needed to start feeding day old parrot chicks and it was pretty clean as far as bacteria. But will look into the UV. Good thought.

As far as a flow restrictor, when I went to the URL above, I learned there isn't anything on my waste water line. The connection to the membrane canister is identical to the good water connection. I did remove the tubing in both to check, and there is nothing extra in the waste line or connection that I can see.

When I first filled my tank (about a month ago) a friend brought over her RO system and we made the water thru that, and on her TDS it was fine. I also made extra for topping off, but getting low now and I imagine it is time for a partial water change too.
Thanks again

[UN-Sizzlers]

Talk to The filter guys , very friendly and they know thier stuff. They even help others customers , wich has gotten them a good rep and futre buisness from them.

[shibumi]

Check this out:

http://reefcentral.com/forums/forumd...s=&forumid=439

[BuckeyeFS]

Yes - you'll need a flow restrictor to get that ratio in line...

Sometimes the flow restrictor is IN the elbow fitting in the waste port on the RO membrane housing. So unscrew that fitting and look inside it for something that resembles a plastic plug or small orifice.

Russ @ BFS

[BuckeyeFS]

Afqu - you may also want to take a look at the FAQ's on our website for more info.

Russ

[afqu]

Okay.......Russ, I have lived on your site for days. All the stuff is written for someone who has at least a basic idea of what is going on.......lol

Anyway, I went into town today and passed a LFS I had never been in, so stopped and asked them for a flow restrictor for a 50GPD membrane. I get this little thingy about 5/8" long and it is a molded into one piece containing a collar and nipple, with a pigtail of black tiny tubing coming out of the other longer end.

I ask the guy how do I use this and he says.........his tech isn't in today, so no clue. I don't even know if I have the right thing.

I just unscrewed the elbow as you suggested, and I see nothing that would make me think there is a restriction device of any kind. Since this may have been originally for 100GPD, should there be one there?
Thaks everyone for your patience,
Jean

[BuckeyeFS]

Now we're getting somewhere!

What you bought is a capillary flow restrictor. Hopefully the restrictor is green - right?

put some teflon tape on the threads of that fitting, and reinstall the elbow fitting. Insert the flow restrictor, tail (capillary tube) first, into the upstream end of the waste tube. The "tail" goes in the downstream position. Just about an 1/8 inch of the restrictor ought to extend from the tube. Insert the end of this waste tube back into the elbow fitting and you are good to go!

Russ

[afqu]

Yep, it's green!

The waste tube (intake end) snugs up to the collar, once the capillary is inserted and that end goes into the elbow. I think I got it.

Hubby is asleep and I don't know where the teflon tape is, so will let yous all know tomorrow..........I can't wait.
Thanks so much
Jean

[BuckeyeFS]

Do you have a pressure gauge on your RODI system? Or just on the holding tank?

[afqu]

HI all......
I do not have a pressure gauge on my RO unit, just the holding tank.
I ran a test twice. The last I was very careful to be exact.
in 13.5 minutes I got............
4 cups good water
1 gallon + 3oz of waste water
the ratio seems good but I am not so sure of the 50 GPD deal.
Thanks again for everyone's help and patience.
Jean

[BuckeyeFS]

Well, if my arithmatic is right, you are at a 4.1 waste :1 permeate - so you are good there.

Out of your 50 gpd membrane, you're getting 27 gallons per day.

I used the calculator on our website to check your membrane production. At 40 psi, and an assummed 65F water temp, you should get about 31 gpd from a 50 gpd Filmtec membrane. If you have a different brand of membrane you should expect less production.

Russ

[BuckeyeFS]

Your membrane wants more pressure!