RO unit

[spotfin]

A question for you all:
I was just given a Kent Marine Bare Bones RO unit. I am thinking about a way to get the most out of it. As you know, two things that make RO units inefficient are low water pressure and low water temp. My water source is a well and the maximum pressure is about 50 psi. Too low by most standards for RO and the temp is too chilly as well. Was wondering about filling a trash can with water, letting it warm up to room temp (or throw a heater in it), and then using a pump to push the water through the ro unit? Would a pump (like a Mag style) be strong enough to reach 65 psi or so? I see that you can buy a special booster pump for RO units but they are very expensive. If the pump has a 1/2" or so outlet, going to the 1/4" hose of the unit, would the increase in pressure be enough? I would put a valve and pressure gauge in-line between the pump and RO unit. Any thoughts?
Jason

[Hedonist]

I am not sure about the tech details, but over all it sounds like a PITA to me..... having to fill a container to make a batch of DI (and wait until it heats to your desired temp) to make how many gallons of water....? Not to mention extra containers of water sitting around :rolleyes:

I sent the question to Craig to see if he wants to comment... I do know you can install a heating unit via your hot water heater.. of course you have to determine if the cost of heating the water is worth it etc....

What pressure do they recommend for ROs.. mine is similar to yours

Denise

[vermonter310]

Jason,

Coiling a few feet (25+/_ in a five gallon bucket and using an aquarium heater has been mentioned on this board befor. This should help warm the water. As for the pressure, My well ranges 40-55psi. It is enough to run the filter but reduces the rejection rate. At least thats how I believe I understand it. I'm not sure off the top how much a MAG pump is but I've seen the RO/DI pumps for as little as $65. (plus 15.00 shipping)

[spotfin]

The recommended psi for the RO unit is 65 psi. My well system ranges from about 35 (before the well pump kicks on) to about 50 psi (when the well pump shuts off).
Wouldn't you need a really long hose to get enough water to go thru the ro unit? It seems that a 1/4" dia meter hose doesn't hold much water per foot.
Mike, where did you see the RO/DI pumps for that price? THe ones I have see have been close to $200!

[vermonter310]

The one I saw was from an ebay vendor. aquasafecanada. Just do a search on ebay for reverse osmosis water filters and you'll find them. you can buy them from thier ebay store for that price.

Mike

[Ewan]

The mag pumps will not come even close to the needed pressure.

I've often wondered about the ebay pumps. I'm very fortunate to have 85 psi water at the house we're renting right now (EXTREMELY high... highest I've ever heard of in a residence) We get some serious efficiency out of our 100gpd RO/DI because of it.

When it comes time to move, I'll buy a booster pump. It used to take us 8 hours to make 5 gallons of water with our old 25gpd system and 40 psi pressure at our old house. It now takes us less than one hour for 5 gallons of RO/DI.

Awesome, huh?

Pressure is the key. I fiddled with temperature at our old place, and it made a minimal impact on volume of product produced.

-Rob

[SaltyDogg]

This is what you can use to boost your water pressure for the r/o unit.

R/O Pump (http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=4473&N=2004+22789)

I am sure that there are other types available at different sites. This should give you a idea tho of where to start......

I have some pictures around here of the unit I made to heat the water up more, will try and find them and post them as well....

Hope this helps............

Bryan-

[SOMEthinsFISHY]

goodole late night bryan !!

[smtarr]

Jason, What I'd do if I was faced with a water pressure that was too low would be to adjust the pressure switch on my water supply pump. Do you have a drilled well with a submerged pump or a dug well with a water pump and tank in your house? If the water pump is in your house there is a box on it that controls the water pressure. I checked with my hubby who has worked on our water pumps for years and he said shouldn't be a problem to adjust the pressure up to say 65 for low and 85 for high pressure. If you feel more comfortable you can get your plummer to do the adjustment since these things are a little tricky. If you're on city water I'm stumped. I just think it would be better to fix the problem at the source if possible. :-) Sue

[Hedonist]

FWIW, I spoke to Craig who deals in these units.. he said the temp is the biggest factor.. considering your temp is close to probably 50? and the ideal is 77......
Most membranes are rated for 50psi, you should be able to confirm this by looking at yours... if your pressure is close to that then I would be more concerned about the temp... you can buy a mixer and hook it into your hot and cold water to deliver the water to the RO at the correct temp.....
Just another spin on this.. don't ya just love it?
Denise

[spotfin]

THanks everyone for your input! I would definately need to get the water pressure up to get the most out of the unit. Sound like I should fiddle with the temp too. We do have a drilled well with pressure tank so might be able to adjust that. Could someone maybe check the tds straight out of the tap for me? Maybe my water isn't too bad to begin with.
Anyone have good or bad luck buying stuff from ebay?

Jason

[Ewan]

I've had great luck. I go for 'sure-things' though. I'll gladly pay more for an item from a person with plenty of positive feedback (and little to no negative feedback).

Good luck. I'm interested to see how you make out. The booster pumps on ebay are an incredible price. Like I've mentioned, I've considered buying one 'just in case' because of the sweet price.

-Rob

[smtarr]

Jason, Yeah, like Denise says the temp is important also. I just run my DI off the faucet and adjust the temp as appropriate. Just DI gets rid of all the cations and anions but I just have to change out the resin cylindars more often. When I get my big tank will switch to RO/DI system but for now the DI works fine, my tap water has 0.5 ppm phosphate and I don't know what else. Measures 0.0 from DI. Sue

[SaltyDogg]

Found those pictures I wanted to show you all of the r/o heater that I made for use in the winter time.....


http://www.finns.biz/bryan/bucket2.jpg

http://www.finns.biz/bryan/bucket1.jpg

[Hedonist]

Bryan, just curious (and skeptcial too I guess)... have you ever taken the temp of the water exiting the set up after the RO unit has been running a while?
While the water may reach opt temp sitting in the bucket for a period of time, what about as fresh, cold water is being pulled from the well when the unit has been running and used the water in the submerged coils... is there enough contact time for the temp to significantly rise?

Denise

[spotfin]

any thoughts on using copper pipe?

[Hedonist]

The RO unit should be removing any traces of copper, just don't use it after the unit...
Denise

[SOMEthinsFISHY]

BRYAN the pictures were not there