buddies ro/di is only pumping like 5 gallons a day, why????

[agoutihead]

my buddy just got a used spectra pure for 50 bucks. looks perfect and basically brand new. he did have to replace all the media in the three lower chambers. there is a 4th on top, the actual 3rd stage of production that he didnt replace.

but for some reason he is only getting a few gallons a day. i would assume one of this size would be able to do at least 25 gallons, if not 50 or 76 a day.

i have one in simlar size and i can do 5 gallons in about 2 hours.

anything we can try or tweak to make this thing pour out faster?

can someone explain all of the different chambers, what their media is and what exactly it does to the water?

the waste water does seems to pour out at a decent rate though.

[carlso63]

Does he have a high enough input water pressure from his tap supply?

[agoutihead]

i would assume so, i mean how do you test the pressure of a copper pipe before you puncture it?

the waste seems to run fine, it would probably produce the 5 gallons in 2 hours or less actually. it seems kind of reveresed.

and why does an ro/di machine "waste" water, why cant it just filter it all? what decides what part is waste and what part is good?

[agoutihead]

bump

[buzzer]

I would assume it is also the pressure,pressure guages are cheap to install to ro units.(mine cost £10)
I would advise him to get one as even if his pressure is ok now it can warn of future issues.

[agoutihead]

what exactly is a pressure gauge? where do you buy them?

[mhurley]

Your buddy needs to figure out what stages he replaced so we can help properly. There's prefiltration, carbon, the RO membrane, possibily a DI stage...etc. Saying he replaced 1-3 doesn't help because every unit is construted differently. Figure out which SpectruPure model he has.

The entire concept around RO is the Reverse Osmosis membrane (that's likely the "top" filter you talked about). That membrane does the filtering between the good water and the waste water. It's just the way RO filtration is...There is waste water that the membrane cannot filter out. That water is still good for other things (people wash cars, do laundry, water plants...etc).

So, if he replaced everything BUT the membrane AND he has good water pressure, I would imagine his problem is the membrane is cashed. If he paid $50 bucks for it, it's even more likely that it's old and needs a new membrane. Sadly, a new membrane is going to cost him as much as he paid for the unit itself.

Regarding water pressure, without getting technical and buying pressure gauges, if you turn on his sink faucet full blast, do you get a blast of water, or is he in an area where it just kind of dribbles out slowly? If it's slow flow, he could have an issue. RO units require pressure to function properly and if his tap has low pressure, the membrane wont filter properly. However if you gets good flow (my non-scientific test above), pressure should not be an issue.

He should be able to contact SpectraPure directly for support.

[AZDesertRat]

I would also suggest contacting Spectrapure. A few things to consider though. They will ask him what his pressure is and what the water temperature is first off so he needs to know those numbers. A pressure gauge that screws on to an outside hose bib is available at any hardware store for less than $10 and he probably already has a thermometer somewhere to measure the water temp. You also need to check that the self piercing valve went all the way in and is opened up fully. Try turning it in all the way and back out again while you have the 1/4" inlet line stuck in the sink or a bucket to see what the flow looks like. This is a common problem with self tapping valves and self installations and will starve the membrane.
Has he timed the flow from the waste and product or good water lines and gotten actual flows? Spectrapure has good troubleshooting guides on their website in .pdf form so you can download the instructions.

[agoutihead]

im not sure what state is what, but i would assume stages 1-4 are all the same in every machine arent they?

i know he replaced, 1, 2, and 4. it was the 3rd chamber, the one with the waste line that he did not replace. the girl at the lfs told him it didnt need to be replaced as often as the other ones, but the other ones were really dirty, so he might have to replace it. honestly we didnt even open it for some reason so i dont even know what, or if anything at all is in there.

what media goes with what stage? is it always the same in every machine?

as far as the "scientific water test" his water pressure seems normal to me, nothing that i would have been worried about.

we pierced the copper pipe a couple of times, but nothing really changed.

an ro/di machine should always be good right, even when used? obviously the media has to be changed, but the containers and hardware should be good fovever shouldnt they?

[AZDesertRat]

The order of filters is pretty standard. Usually left to right its
1. Prefilter- sediment or particulate filter in the 0.2 to 10 micron range
2. Carbon filter- Most reef type units use a solid carbon block in the 0.5 to 5 micron range. Some units have two carbon blocks but its not necessary. Most drinking water type systems use granular carbon which is not desireable since it grinds itself to dust over time and can plug the membrane. The lower the micron rating he more chlorine it will adsorb.
3. From the carbon it travels up to the membrane which lays horizontal on the top. Membranes vary from about 15 GPD up to 100 GPD with 75 GPD being the most common.
4. Back down to the DI or deionizing filter which is usually the last canister on the right or sometimes on lesser units it's a smaller horizontal tube on the top. The full sized vertical canisters are preffered since they hold more DI resin and filter better due to their configuration.

Membranes do wear out or can go bad if not used for some time and stored dry. Once in use a membrane needs to stay wetted.
In order to determine if its bad or not you need to test with a TDS meter, pressure gauge, thermometer and measure the good water output and waste water output with a measuring cup and watch to time the flows. Without all that information its just a guess. Pressure and temperature have the biggest effect on output.

[agoutihead]

well chances are his membrane is trashed. its the only thing i can think of with "just a guess"

it was a used system, and god only knows how long it was just sitting there unused. he had to give it a pretty good cleaning in the other stages, so i would assume that the membrane is junk along with it sititng for so long.

are membranes generally expensive?

[aquarius77]

No they are not too bad really. 45 bucks plus shipping from the filter guys will get you a 98 percent rejection rate 75gpd dow filmtec membrane.

[agoutihead]

man 45 bucks sounds like a lot for a filter!

ebay is probably the cheapest i would assume?

[AZDesertRat]

No.
You have to be very careful who you buy from on e-bay when it comes to RO/DI components. Cheap usually indicates poor quality and there are lots of foreign knock offs that visibly look the same but do not perform or last like the real thing.
For the best prices and service stick with people like sponsors here on RC who will not rip you off
www.thefilterguys.biz
www.buckeyefieldsupply.com
www.purelyh2o.com
www.spectrapure.com
$45 is very reasonable for something that will last you 3-5 years or longer if taken care of.