RO/DI--people who have it can you help me?

[digital-audiophile]

I've found similar on my unit that I just set up a couple weeks back. I am getting TDS of 2-4 with brand new media.

[Delphinus]

Between the RO and DI or after the DI?

[sharuq1]

The tap TDS is about 225 or so I think. The 6ppm is what is coming out of the unit, after the DI and polishing filter thing. Should I take the "polishing filter" off the unit? It is on after the DI, then the DI goes to the storage container dealie. (not sump, this is the container aquasafe sends with their maximus unit for home use).

I haven't checked psi (I don't know how, especially without spraying the house down with water i see no where I can put a psi measurer thingie) , but I really don't think the psi is the problem as I was getting 0 reading before and I am in the city not the country.

I don't know how to backflush the membrane.... If backflushing means turning the wastewater as high as it can go for a few mins then yes I have done that, but it didn't help.

The unit is plumbed into a tap and is turned on or off using the valve that is on the input line. It is not hooked up to a sump or anything like that. The DI does look like it is almost exhausted, but I just don't know why. Should I be turning the wastewater so high that it is a flow and the RO coming out is a mere occasional drip??

It looks just like this unit:
http://www.aquasafecanada.com/MAXIMUS%20II.jpg
http://www.aquasafecanada.com/MAXIMU...TOP%20VIEW.JPG

[Myka]

Check the tds of the the water that comes out of the RO, but BEFORE the DI. You'll have to take it apart to do that. Just disconnect the line between the RO and the DI, and collect that water to test it. How many gpd is your RO?

[sharuq1]

TDS there is 18. The unit is supposed to be 100gpd. Also TDS before "polishing" filter (after DI) is same as what is coming out when polishing filter is hooked up, so guess it isn't that.

[littlesilvermax]

Originally Posted by sharuq1

TDS there is 18. The unit is supposed to be 100gpd. Also TDS before "polishing" filter (after DI) is same as what is coming out when polishing filter is hooked up, so guess it isn't that.

If your post RO tds is 18 ppm, then you have one of three things:

1) very high tds water (like 600 or so) and it exhausts your DI quickly
2) a bad membrane (FWIW the 75 gpd, I like the Filmtec, seem to consistently outperform the 100 gpd ones)
3) very low pressure to the unit

How to solve the problems:

1) just have to live with it (BTW someone around here has awesome deals on DI resin)
2) get a new mambrane, and by the sounds of how much you are using stick with the 75 gpd ones
3) get a booster pump

FWIW even if your pressure is good, a booster pump wil up efficiency, that is why I bought one.

[Myka]

The membranes have different efficiency rates.

Filmtec 50 gpd = 98% rejection rate
Filmtec 75 gpd = 98%
Filmtec 100 gpd = 90%
BFS 150 gpd = 98%

If your tap water is 225 ppm, and you're getting 18 ppm out of the RO, then your efficiency is about 92%. If I were you, I would change out your flow restrictor for a 75 gpd, and get a 75 gph membrane that is 98% efficient. This way you should get about 4-5 ppm out of the RO, and your DI resin will last much, much longer. This is probably your cheapest solution.

[banditpowdercoat]

My source is 500-700PPM, and I routinely get 10-11PPM after DI

[morph]

Hi there This is my understanding of flushing the membrane Just before your waste water moves away from the body of the filter Should be the yellow hose there is a white thing clipped on to the filter it has a black handle . the handle should be turned across the direction of the pipe to make ro water you would think your turning off the filter but thats how it works. to flush the membrane turn the black handle the same direction as the pipe let the filter continue to make water for about 20 minutes threw out that water . now turn it back across the pipe do this once a month

[digital-audiophile]

Originally Posted by Delphinus

Between the RO and DI or after the DI?

I'm getting the readings after the RO and DI.