RO reject water

[Jim H.]

I would like to start using my RO reject water. Would some of you share your ideas on how to do this? I figure there is know since in reinventing the wheel. Thank you

 

[Waxman]

There are previous posts about this. I think Galen added some photos of his setup as well.

 

[Jimmy Buffett]

Look in the library at the top of the page.

 

[newhampshiretech]

we had been adding this as a feature when installing new washes when I worked with a distributor. not sure how extreme you want to go. we would dump ro reject to holding tank that would overflow to drain if necessary. then put a pump and bladder tank from that holding tank and tee into the main water feed after a check valve so all units would get the reject water even washing down bays etc... just have to insure there is a check so as not to feed back to city and the Ro unit needs to be fed prior to the check so its not getting concentrated tds water sent to it.

 

[Jim H.]

I have got to start using spell check (no sense in reinventing the wheel). I appreciate the help. I have tried a search, but didn't know there was anything in the library about it. Thank you, Jim H.

 

[MEP001]

For that type of "spell check," you'd need to write in Microsoft Word that can also check grammar. You spelled "know" and "since" correctly, and a simple spell-check wouldn't have caught it.

My preference is to use a storage tank and pressurize the water to a second float valve in the automatic tank that's higher than the one on city water. You'd only need a pump with bladder storage, a tank, a float valve and a low-water cutoff switch that will disable the pump if the tank is empty. You'd want an overflow on the storage tank so if the pump fails it won't make a mess.

 

[I.B. Washincars]

I don't understand all of these over-engineered ways of using the reject water. If your auto pumping plant is in the eq. room it should be as simple as buying a tank and setting it up on blocks to get it above the pump inlet. When I did it on my old Mark VII Rotoclean it cost me the price of a tank and a couple of hours for a plumber. Here is what I did,

Elevated a 300 gallon tank next to the pumping plant.

Disconnected the fill from the original tank and routed it to the manhole of the new tank.

Moved the fill and low level switches to the new tank, putting the low level switch a couple inches higher than the outlet fitting, the fill switch about a foot higher. Disregard the fill switch reference if you will be using a float valve. This leaves room for about 200-250 gallons of reject water to be dumped on top of the water already in the tank.

Plumb the outlet of the new tank to the HP pump.

You're done!

Everyone seems to be hung up on using the existing supply tank which just complicates the $h!+ out of it. Ignore the old tank and life will be much easier...been there, done that.

 

[dogwasher]

I don't understand all of these over-engineered ways of using the reject water. If your auto pumping plant is in the eq. room it should be as simple as buying a tank and setting it up on blocks to get it above the pump inlet. When I did it on my old Mark VII Rotoclean it cost me the price of a tank and a couple of hours for a plumber. Here is what I did,

Elevated a 300 gallon tank next to the pumping plant.

Disconnected the fill from the original tank and routed it to the manhole of the new tank.

Moved the fill and low level switches to the new tank, putting the low level switch a couple inches higher than the outlet fitting, the fill switch about a foot higher. Disregard the fill switch reference if you will be using a float valve. This leaves room for about 200-250 gallons of reject water to be dumped on top of the water already in the tank.

Plumb the outlet of the new tank to the HP pump.

You're done!

Everyone seems to be hung up on using the existing supply tank which just complicates the $h!+ out of it. Ignore the old tank and life will be much easier...been there, done that.

I have been thinking for a few days about doing what MEP had just mentioned(pipeing a new holding tank to my existing automatic holding tank with its own float above the existing float)
If I understand your post your saying just get rid of my existing 80 gallon(approx?) holding tank for my automatic and install a 300 gallon tank in its place so I can have that extra 220 gallons of empty tank for RO reject.
In my case I need a large holding tank you can see my post from the other day in the general discussion section. I like all the comments!

 

[newhampshiretech]

I don't understand all of these over-engineered ways of using the reject water. If your auto pumping plant is in the eq. room it should be as simple as buying a tank and setting it up on blocks to get it above the pump inlet. When I did it on my old Mark VII Rotoclean it cost me the price of a tank and a couple of hours for a plumber. Here is what I did,

Elevated a 300 gallon tank next to the pumping plant.

Disconnected the fill from the original tank and routed it to the manhole of the new tank.

Moved the fill and low level switches to the new tank, putting the low level switch a couple inches higher than the outlet fitting, the fill switch about a foot higher. Disregard the fill switch reference if you will be using a float valve. This leaves room for about 200-250 gallons of reject water to be dumped on top of the water already in the tank.

Plumb the outlet of the new tank to the HP pump.

You're done!

Everyone seems to be hung up on using the existing supply tank which just complicates the $h!+ out of it. Ignore the old tank and life will be much easier...been there, done that.

I dont think its over engineered at all. and I suppose I should have mentioned we use this for 750 -1500 gal tank. I guess if your only saving and reusing 250 gal why put any effort into it.

 

[I.B. Washincars]

My auto used it faster than the RO machine rejected it. It never overflowed and I never wasted a drop of reject water. The only time that you should need an exceptionally large tank would be if the product tank were very low on a busy day and then the business suddenly stopped (auto broke down, started raining, etc.).

 

[newhampshiretech]

I think the other difference is we use pureclean ro unit that auto-regenerates on time by a PLC. so if we have two rainy days the ro tank is full but the units back wash a few times creating ro and ro reject. when no ro water was used to wash cars because of the weather. so we have the ro overflow to the reject then the reject overflow to drain if needed. different applications different needs I guess. either set-up works just depends what your doing and with what volume. we use the big tanks.

 

[MEP001]

Our Alamo brand RO system flushes every hour as well as before each fill cycle, so I wired a float switch to the pretreatment interlock to prevent it from flushing if the reject tank is full. There's no need for it to flush on a slow day.

 

[dogwasher]

For that type of "spell check," you'd need to write in Microsoft Word that can also check grammar. You spelled "know" and "since" correctly, and a simple spell-check wouldn't have caught it.

My preference is to use a storage tank and pressurize the water to a second float valve in the automatic tank that's higher than the one on city water. You'd only need a pump with bladder storage, a tank, a float valve and a low-water cutoff switch that will disable the pump if the tank is empty. You'd want an overflow on the storage tank so if the pump fails it won't make a mess.

Thanks for your help MEP, Could you tell me where I would purchase all these parts and exactly what kind of pump your talking about? What type of float valve would you use?
I think this is how I want to set up my wash.

 

[MEP001]

With a bladder tank you'd use the same type of float valve you're already using. Harbor Freight has a bladder tank and stainless steel pump assembly for $99 that you just plumb in and out and plug in. The float switches you can get almost anywhere - the one I like is a blue and yellow one that has contacts for both close on rise and close on drop. We used to get them from Specialty Equipment.

 

[dogwasher]

With a bladder tank you'd use the same type of float valve you're already using. Harbor Freight has a bladder tank and stainless steel pump assembly for $99 that you just plumb in and out and plug in. The float switches you can get almost anywhere - the one I like is a blue and yellow one that has contacts for both close on rise and close on drop. We used to get them from Specialty Equipment.

Sorry for my inexperience but could you tell me the purpose of the bladder?I believe I found the Arbor frieght ITEM 47906-1VGA with 5 gallon tank connected to it.
If I pump the water to my rinse tank I then pipe it "threw" a float switch?
And then I also need a second float switch in the rinse tank to turn on the Arbor frieght pump?

 

[MEP001]

You could use a float switch in the tank instead of a float valve, then the switch would turn the pump on and off. In that case, you'd probably want a low-volume pump so it wouldn't kick on and off excessively if the draw from the tank is slow. If you used a float valve supplied by a bladder tank, the valve would act just as if it had city pressure behind it, and the bladder emptying and filling would turn the pump on and off as needed.