RO System

[schatzi]

I have a question on installation of a reverse osmosis system. The systems I see for sale at marine supply outlets usually don't include a storge tank or faucet piece which is unlike when looking at systems that are not on fish supply sites (like Sears, Lowes). How do people usually hook up an RO system for a fish tank? Does it directly supply your sump or main tank? I would like to install it to use in the kitchen and then pull water from it when doing tank top offs. Can anyone give me an idea if I'm in the ballpark here? Am I missing something? This really shouldn't be this hard, maybe I'm in information overload with all the new things I'm learning.

Thanks for any input. It's much appreciated.

[kcress]

Hey schatzi. Welcome to AC.

You need a fixture and a bladder tank and the automatic valve. I highly recommend using any RO system for special household stuff too. We only drink and cook with it around our place. And like all RO systems more use equals a healthier RO system.

You need to be very careful when directly feeding a sump or tank with RO/DI. A leaking control valve can be the death of your entire tank because the RO just keeps on giving. I manually turn a valve on and have forgotten twice. I have a high level cut off that starts galloping my closed system pump and eventually someone notices and comes to the rescue. Most users have a holding tank that the RO/DI system feeds then they draw from that to the main tank. But you can go either way.

As I describe below having a storage tank gets you about 4 gallons always ready. Very nice for a bulk top up. If you are making a big change batch up, it won't make much difference though, as you will likely need far more than the bladder tank will hold and eventually you will just be waiting at the RO's GPD output.

There are lots of places to get bladder tanks, often called pressure tanks too. You need not get one from the same place you get the RO either.

If you just get an "RO" or "RO/DI" you aren't going to get storage or the all important automatic control valve that turns off the RO once the tank has reached the water supply pressure.

I get my stuff at Spectrapure.com Not the least expensive but excellent quality.

Here's the "Drinking water stuff".
http://www.spectrapure.com/drinking_water_systems.htm





Here is a hack out of a previous thread on the subject.
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Let me describe it to you. If that doesn't cut it I will crawl under my messy sink and try to get a picture for you.

I will describe an RO unit which in most cases is probably more than enough.

The reason I think RO is enough is because you run the city water thru a sediment filter then a carbon block filter that removes a huge amount of everything there. Especially Iron, Chlorine, and Fluoride. Then the RO membrane reduces anything remaining down to 95% or less of the pre-filtered water which is really removing a lot.

We're talking saltwater - The Ocean - which essentially has everything you can imagine already dissolved in it so having minuscule amounts of a few elements still present seems to me to not be a hazard.. Or fish food and other things would likely cause problems too. But if you are doing something really special or seem to be having water related problems even though your RO system is running correctly, if your city water has a particularly heavy concentration of something then add DI later. Just install things like you will add it. Then you won't ever have to, and you will save yourself the hassle and expense of DI. If you don't plan for it... Then of course you will need it. LOL

So anyway - to the install of an under-sink automatic, tanked RO system.

I will describe how it should be installed.

1) You will have the source. This is the tap water. You disconnect the cold water to the sink on the sink side of the cold water valve under the sink.

2) Screw a Tee in next and the appropriate fitting so your faucet can be reattached as normal.

3)In the other side of the Tee screw in a nylon valve of the type used with the tubing provided with RO systems.

4) Turn off this valve! And turn on the original cold sink valve. Now you can use the sink again. Housemates are happy and the pressure is off of you.

5) Next there is the waste water. This is what's rejected from the membrane. It is 3-4 times the volume of the "Product" which is the standard term for the made RO water. This water needs to be disposed of. The standard way is to plumb it to the drain. The typical way to do this, (and I used this method for 12 Years), is to tap into your sink's drain pipe.

6) Tapping into your sink drain pipe is done by finding the size of your RO membranes waste output line. Most of this stuff is 1/4" tubing but sometimes the waste line is 3/8" because RO waste water under pressure must transition to gravity flow for legal reasons. This means larger tubing.

7) Once you have the tubing to straight male pipe thread (NPT) fitting, find a location on your under-sink drain pipe above the P-trap and drill the right size hole in the PVC. Using the appropriate male NPT tap, tap the hole you just drilled. Teflon tape the male pipe threaded end of your tubing adapter and screw it in snugly. It doesn't need to be real tight! Just not leak.

8) Now if you have an ancient metal trap under your sink then I would just change it out for plastic since this is one case where plastic is vastly superior to metal anyway. You can buy entire plastic replacement kits for this stuff at any hardware store for about $5.

9) So now you have the source water with a valve and a drain, probably 3/8". You're ready to actually start the major install. (Don't worry it's not too hard)

10) Locate where you're going to put the mini faucet so you and everyone else can reap some personal benefits of great orange juice and coffee, etc. Hopefully you have a waiting knockout-cover on your sink deck. If not and your sink deck is steel you can get the correct hole saw and put one in. Before you drill though look carefully at the mini-faucet and understand how it mounts and the small amount of room it needs under the deck to be mounted. You wouldn't want to drill the deck in the wrong place.

11) OK, you have the hole in the deck the mini-facet will have three hoses going to it. One is the product 1/4". One is the pressurized RO waste water 1/4". And the last is the gravity drain of the aforementioned RO waste water 3/8".

The waste is run to the mini faucet where it is shot thru an air gap to the gravity drain line. This is a Federal requirement to disconnect the sewer from the home's pressurized tap water. Things can go wrong on the city side that causes the city pressure to go negative. This would suck back sewage into a city's freshwater supply. We can all agree this would be... BAD! There's a little hole in the facet that creates this "vacuum break".

12) Making sure all three tubings are correctly hooked to the mini faucet, poke them all down the hole and install the faucet. Usually some sort of clamping device from underneath pulls down on the faucet sealing it via its upper deck gasket.

The hard parts are all done!

13) Next figure out where you want to set the little bladder tank. They come with a little plastic dog bowl stand. They are about a foot in diameter and maybe 14" tall. Picture about 3.5 gallons of space mashed into the smallest volume possible. Set the tank in place. They weight about as much as one red brick. (Light)

14) Now on one side or the other or even the back of the cupboard hold up the RO unit. It will include a sediment filter (vertical), and a carbon block filter(vertical), the membrane/housing, (horizontal on the top) and the automatic control valve - about the size of a tangerine.

Figure out where you want, it remembering that you want to service this thing once in a while. They recommend changing the filters once or twice a year. To be honest I do it about every three years. For me, this is way before the carbon block is exhausted and any notice of increasing TDS readings has occurred and I get 8 years out of my membranes!!

15) Once you find a nice location for the conglomerate screw it to the wall.


16) You run the tap water to the sediment filter.

I am always totally shocked by these sediment filters when I finally change them. You put them in and they are dry, pristine white and weigh maybe 10ozs. Take them out they are rust mucking, putrid brown, and weigh perhaps 5 pounds and it isn't the water...

17) Next the water goes from the sediment filter to the carbon block filter. Why is it called a block? Because that's exactly what it is; a compressed solid block of carbon with 5 micron pores through it. BTW this connection is made usually in the factory kit you've gotten.

18) Next the carbon filter feeds the inlet of the membrane. Here you should add something the kit people rarely do. Put in a 1/4" tee and a valve and some tubing. Why? Because the first thing you need to do when commissioning after a filter change is run a bunch of water thru the two prefilters. The carbon filter will have carbon fines.. Black powder. This powder will wreck your membrane so you need to flush this out into a pail or if you use long enough tubing into the sink.. Just run a few gallons thru until no fines are present.

19) This prefiltered water then runs to the automatic valve. From the valve it runs to the membrane inlet.

20) From the membrane product outlet you run back to the automatic valve again.

21) From there you head off to a Tee on the top of the tank.

22) The Automatic Valve looks at the pressure of the prefiltered water and the pressure in the tank. If the pressure difference exceeds 'so much' then the valve opens and water production begins again. This keeps the bladder tank charged up. So whenever you need it you have about 3G of water waiting for instant use.

23) From the top of the bladder tank's TEE you run a line to a polishing filter. A small in-line filter generally added for taste reasons. It is a small carbon filter. This only goes to the faucet.

24) From the polishing filter you run to the mini faucet.

25) Now for the aquarium you put a TEE in the line from the Automatic Valve to the tank. Then add a little valve. Then run your line from the valve to your aquarium for make up, etc.. At the Aquarium you can have whatever splitter or valves or floats or???

26) Lastly you run the pressure waste line from the membrane to the correct mini-faucet line.

27) And the 3/8" gravity drain down to the P-Trap fitting you put in earlier.

That's it.

Every once in a while you should do a Chlorine test using that valve in the line from the primary filters. If you detect any chlorine at all you are cooking your membrane and need to change the primaries immediately, if not sooner!

A lot of this will be preassembled when you buy a system.

They all use really simple nice little plastic fittings that need no tools.

Get a very clear picture of what they will provide with their system. Then draw a schematic of what you really need for convenience and functionality. Check off what you will get with the system then add the plastic Tees, valves, and adapters, you need to do your system right. Add them to your order. They are pretty inexpensive. Get a few spares.

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Here are some others:
Good reading that shows some common mistakes that can damage your gear.


http://www.aquariacentral.com/forums/showthread.php?t=157154
http://www.aquariacentral.com/forums/showthread.php?t=165112
http://www.aquariacentral.com/forums/showthread.php?t=151331
http://www.aquariacentral.com/forums/showthread.php?t=154799
http://www.aquariacentral.com/forums/showthread.php?t=155681