urgent help with my ro unit

[essaf victor]

hi
so I have problem with my ro unit
1)its brand new only 2 days old so all the cartridges are good
2)the ro membrane in labeled as 97% rejection rate and my tap water comes out as 220 tds so in theory after the water passes throw the unit it is supposed to come out as 6.6-7 tds
3)all the connections are correct am confident in that
4)the system has been flushed for several ours so its supposed to be clean on the inside

so its supposed to be working fine by now

but what is actually happening and driving me crazy is that in the morning the water coming out of the ro unit was 120 tds so I left working to flush it self and by 5pm (its been flushing for over 5 hours) then the tds went down to 60 then two hours later to 25 went back up to 45 and stayed still their for 3 hours till now and it doesn't want to get less its fixed on 45 which is no were near 7

please suggest any help because my tank has been ready for water with all its equipment ready to go for a week waiting for the ro unit to work


thanks in advance

 

[essaf victor]

and one more question what happens when my ro unit produces more than its advertised limit, does water quality go down or what

 

[lakai]

Whats your water pressure ? do you have the correct flow restrictor? post a pic of your setup. Is your TDS meter after the membrane?

 

[essaf victor]

Whats your water pressure ? do you have the correct flow restrictor? post a pic of your setup. Is your TDS meter after the membrane?

 

[FishTruck]

To check the flow restrictor... check your waste to product ratio. It should be something like 5:1. I use a needle valve instead of cutting the restrictor tube to length, so that I can tinker with it. I try to hit 0-1 tds after the membrane... and if I push the waste water too low, the tds goes up.

I get two buckets, make marks every inch with a marker, and run the waste into one, and the product into the other. Research your particular unit and set the waste / product ratio accordingly. I do this every time I change my membrane.

If you can't get decent water production with your ratio set at 5:1, then your water pressure is too low. Or... if your unit has a gauge you can measure it. Higher output membranes require more water pressure. I see you have a booster built on the unit - so your pressure should be fine.

If you push your unit to more than it's advertised limit (waste / product 1:1 for example), your tds will go up and the membrane is more likely to fail or rupture.

 

[essaf victor]

Whats your water pressure ? do you have the correct flow restrictor? post a pic of your setup. Is your TDS meter after the membrane?

I don't know my water pressure I use a hand held tds meter

 

[Terry Mattson]

So have a 5 stage ro/di unit. The unit has 4 TDs meter measurement points. The sourse water supply is 279. Post membrane is 5, post next filter is 2, and post di is 0. Check the system is plumbed correctly. The carterages are in the correct order. My pressure is about 60 psi however I added a pressure pump to bring it to 80 psi. Production is improved by 33 percent.

 

[essaf victor]

To check the flow restrictor... check your waste to product ratio. It should be something like 5:1. I use a needle valve instead of cutting the restrictor tube to length, so that I can tinker with it. I try to hit 0-1 tds after the membrane... and if I push the waste water too low, the tds goes up.

I get two buckets, make marks every inch with a marker, and run the waste into one, and the product into the other. Research your particular unit and set the waste / product ratio accordingly. I do this every time I change my membrane.

If you can't get decent water production with your ratio set at 5:1, then your water pressure is too low. Or... if your unit has a gauge you can measure it. Higher output membranes require more water pressure.

If you push your unit to more than it's advertised limit (waste / product 1:1 for example), your tds will go up and the membrane is more likely to fail or rupture.

is this the needle valve you are talking about

 

[FishTruck]

Yes that appears to be it... that valve should be on one of two lines that come out of the membrane chamber.

The restrictor should be on the "waste" line, and the other one is the "product" line. The product line goes on to the DI chamber and should have no restriction. That valve basically controls the pressure that forces your water across the membrane.

Put each of those outputs into containers of equal size..., and the outflow rate should be about 5 parts waste to every 1 part product. As you crank down on the needle valve, your product ratio will increase at the cost of less purity, and eventually breaking the membrane.

Some high end set-ups can handle 3 to 1 - but not mine.

 

[Opus]

I don't think the needle valve is the restrictor. It looks like it has a barrel style restrictor in the third picture and it is on the waste line. I would take the RO membrane out and reseat it just to make sure it was installed correctly and that the seal was not off. If it is not perfect some of the regular water can get thru and raise the tds of your product water. If still having tds issues then check the ratio of bad to good water and let us know the numbers.

 

[FishTruck]

I don't think the needle valve is the restrictor. It looks like it has a barrel style restrictor in the third picture and it is on the waste line. I would take the RO membrane out and reseat it just to make sure it was installed correctly and that the seal was not off. If it is not perfect some of the regular water can get thru and raise the tds of your product water. If still having tds issues then check the ratio of bad to good water and let us know the numbers.

Right... you have to see which line it is attached to. It can be a barrel, needle, or in the old ones... just a long piece of tiny tubing that had to be cut to length. With those high TDS numbers... I would also agree that it might be a seal issue or blown membrane. IF it is that... then you will have to adjust your ratio twice, once before you fix the seal and again afterwards.

 

[ironman187]

So, I don't see any DI resin canisters. You should be seeing under 6TDS coming out of your RO filter. As others have said, your rejection rate probably isn't set right. I love the idea of using a needle valve for manually adjusting, but it's definitely more complicated than the pre-set restrictors. Whatever the case, if you don't have a DI filter on your system, you need to add one.