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Need advise on RO reject pump

dogwasher

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I Need advise on what kind of pump I should purchase for my RO reject tank.
I have a Grainger book open and Im not sure what pump to buy?
I have a 300 gallon holding tank, pump to be mounted one foot above the tank(I could mount it on the floor if needed) then it pumps the RO reject water 18 feet over to two rinse tanks operated by float valves.
Looks like I should also purchase a Expansion tank?
Thanks for any help!
 

jcollins

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If you could put that holding tank on legs and get it up close to the ceiling (may need a horizontal tank), you could "gravity" feed the water back down to the rinse tanks saving the money for a pump and the electricity to run it. ........just a thiught.
 

dogwasher

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Thanks but I do not have the ceiling hight or the support that is needed to raise the tank
 

washnvac

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I have an equipment room tight on space as well. I set the floats in both automatic feed tanks to 50% of the reserve, then I "T"d the reject line and ran it to both tanks. This feeds about half to each reserve tank. I figure there is about 50 gallons of capacity in each one. But when spot-free is in production, most likely the autos are both running. There is an occassional loss at the end of the day when business has slowed, but the spot free is still catching up. I accept this as the cost not to have additional tanks or pumps.
 

waright

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use a g5700 flojet, a nc 110v solenoid for air to the flojet, a low water cutoff float in the reject tank, and a $10 suttner rinse tank float valve. you should have a low water cutoff float no matter which kind of pump you use. the reject tank will run empty sometimes. $150 or less in parts.
 

MEP001

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I use a Flojet as a transfer pump and one to spray over a powder soap basket. They're cheap and reliable, and you could use a float valve in the feed tank with a float switch in the storage tank to shut off the Flojet if the tank runs empty.
 

DivineSuccess

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I just got done plumbing in my reject tank. I used a sta-rite 2 1/2 hp pump be cause I had an extra one laying around. I plumbed that to a bladder tank (20 gal) that I bought at lowes wired in a pressure switch and I was good to go. I use it for 4 hydro-minders and a hose bib. It was a great cash saver and the project was cheap and easy.

I wish I could have done the gravity way but this wasn't too difficult.
 

brett

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I am going to install my RO reject pump tomorrow. I use a Zoeller 120V sump pump ($120) with built in float. The pump is supplied with power by a relay connected to the high pressure pump motor contactor on my Washworld. The pump only pumps water when the automatic is running. When the reject tank runs dry the sump pump's built in float will turn the pump off. No float valves are involved since the sump pump can not pump water faster than my Cat 3535 can consume it. Not one drop of reject water ever makes it to the drain.
 
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I.B. Washincars

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I don't understand what the reject pump is for. I can't imagine not having enough headroom to elevate the tank 3' so it will just gravity feed to the HP pump.
 

dogwasher

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I don't understand what the reject pump is for. I can't imagine not having enough headroom to elevate the tank 3' so it will just gravity feed to the HP pump.

My reject holding tank is about 7' tall and on top of a 2'stand, ceiling is about 10', the floats they feed are at about 6' so I have to use a pump. Thats interesting what you said about feeding the HP pump..I thought about that because that would work without a reject pump but what would happen when the reject tank ran dry? Are you taking about using a tee to tie into the feed hose that runs from my rinse tanks to my HP pump?
 

I.B. Washincars

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You don't feed your original rinse tank, you forget that you ever had it. What I did on my old Mark VII was elevate a tank next to the pump stand. I moved the low level switch from the original tank to the new one and placed it about 6" from the bottom. I moved the fill switch and installed it about 1' above the low switch. I moved the supply from the original tank and pointed into the manhole on the new tank. This kept about 18" of water in it at any time, leaving about 3' above that level for any reject. It worked flawlessly for several years until I replaced that machine.

Note: My machine used a solenoid valve and switch for filling. If yours uses a float valve it should be a bit easier, just ignore the part about the "fill" switch and install your float at that level.
 

DivineSuccess

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I didn't have the three foot tank. I had three 500 gal upright tanks so I converted two of them to reject water tanks. It wasn't worth it to elevate the big tanks.
 

Indiana Wash

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I am going to install my RO reject pump tomorrow. I use a Zoeller 120V sump pump ($120) with built in float. The pump is supplied with power by a relay connected to the high pressure pump motor contactor on my Washworld. The pump only pumps water when the automatic is running. When the reject tank runs dry the sump pump's built in float will turn the pump off. No float valves are involved since the sump pump can not pump water faster than my Cat 3535 can consume it. Not one drop of reject water ever makes it to the drain.
Sounds great, but how big of a holding tank do you have? You say that not one drop of reject water ever makes it to the drain, but you say you are going to install it tomorrow. That leaves me a little confused.
 

cebo

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I just set mine up a couple of weeks ago and just bought a shallow well jet pump at lowes. It was $250 (100 less than grainger), but looks identical to one in harbor freight for $99. I tied a float switch to stop the pump if the tanks runs dry. Works great and should have done this years ago.
 

Waxman

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I used a "Little Giant" pump w/2 floats. One a low level to prohibit a run dry situation and the other run in tandem w/city water float in my IBA feed tank.

Don't have the model # handy, but pump cost about $250.

I had a plumber do the work so it'd be reliable.
 
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