RO system problem

[sales weasel]

Connected my new RO system today using a faucet adapter in our laundry room sink. That part worked beautifully. However, my TDS is higher coming out (43 vs 41...yes it's that low going in) of the the 6-stage system than it is going in. It is definitely connected properly as far as flow direction. I checked the TDS meter against store bought water and that came in at 0.

I'm not using a tank. My RO system has a ball valve on the waste line to create back pressure which forces water through the membranes. I flushed for at least 30-min and the manual only said 10-min. When I first connected it, the water coming out of the final stage was brown. I'm not sure if I should have run water through the first three filters first and out the waste valve. Maybe by not doing that first, I ruined the final three stages. It came with a complete set of replacement filters which I hate to use them since it's brand new.
Any ideas?

[poppin_fresh]

I dont think you ruined anything. Are you sure that the you are using the correct output on the membrane? What is the TDS of the water coming out of the waste line? It should be higher than the regular water because you are concentrating the bad stuff in it.

You might also want to let it make water for a little while. It takes several gallons to flush all of the carbon and stuff out of the prefilters.

[sales weasel]

Thanks Jon,
I actually made 10-gal and it is still coming out high. Also, the waste water was coming out about 42ppm...right between water in and the outlet. Somethin aint right;)

[GMGQ]

I read that there's initially some carbon dust that has to wash off, and that will give elevated ratings for a while. Give it a few days I guess.

[sales weasel]

One problem was the 4th stage RO membrane wasn't installed. Now, I'm only getting a trickle of water from the final output and it is now over 100ppm. The 4th stage is inserted correctly and will only go one way. I'm wondering if I have enough pressure. Since I'm not using a tank, I don't have a pressure guage. I may take a trip to HD to see if I can find a screw on model. I'm using a faucet adapter instead of tapping directly into the water line.

[MCary]

If the water is going through your RO membrane then there is absolutely no way the TDS's can be higher than your feed water. The water must be getting around the membrane some how. Are there any missing o-rings? Is it a new membrane? Is it damaged? An RO system is very simple. First filter filters out large particles. Second filter is carbon to remove Chlorine and other substances that can harm your RO membrane. Then your RO mebrane which is just a semi-permeable substance that only allow ions of a certain size pass through, Those water molecules bound with something can't fit through and are flushed out the waste line. The final stage of a 4 stage unit is deionization resins.

You should waste 3-4 times more water than you produce. If you close the ball valve on your waste line too far you will damage your membrane.

The pressure from a faucet adapter will be the same as the pressure from a saddle valve in the line. If you need more get a boost pump.

[sales weasel]

Here's a description of my system:
6 stages:
#1 pre-filter 5 micron RO
#2 pre-filter carbon
#3 pre-filter coconut carbon block
#4 RO membrane
#5 Post filter DI
#6 In-line filter, granular activated carbon

My RO membrane was sealed in a vacuum package. It has a blue cover around it and ONLY the ends are open. Based on this, water can only enter the cartridge from the end and pass all the way down the filter. Also, both O-Rings are there. Something tells me that this blue cover should not be over the RO membrane cartridge. If it is like the other filters, water should through and around the filter cartridge. The set-up instructions don't say to remove the covering. Should I????????

[AZDesertRat]

No. Water enters one end and exits the other. Thats why the ends have o ring seals. One thing is disconnect the final carbon filter. It is only needed for drinking water and can actually add particles back in.

[sales weasel]

I disconnected the lines just after the RO membrane and nothing was getting through. I may have a water pressure issue. I'm on city water so there must be a regulator problem or something else. I have an irrigation system in the yard and I'm wondering if this has somehow caused my low pressure? Damn!

[sales weasel]

Yep, the filter is working, I'm just not getting a high flow rate. I'm going to time this thing to see how long it takes to make a gallon.

[ficklefins]

Sales,

We may have the same system, if you got yours from aquadirect on Ebay. AZDesertRat is correct. You really don't need that carbon filter at the end. I think it is there more to flavor the water then anything else, (as RO/DI water has no taste).

Anyways, I got better output from my system when I warmed the water going into it. I used a method that Melev suggested which was running a length of longer hose through a bucket of warm water. You can use a heater to get the water to 80deg but it definetly helped my output.

Good RO/DI read.

http://www.reefcentral.com/modules.php?s=&name=Content&pa=showpage&pid=2

[sales weasel]

Interesting. I'll try that. I actually got mine from RO filter Depot on ebay. I got my faucet adapter from Aquadirect.

Thanks!

[AZDesertRat]

Unfortunately most of the e-bay vendors use 100 GPD membranes which are only 90% efficient and also require 65 psi to produce anywhere near their rated flow at 77 degrees F. I always recommend a 75 GPD Dow Filmtec membrane which is 98% efficient and produces its rated flow at only 50 psi pressure and 77 degrees. If your water is only in the 40 to 50 TDS range the 100 GPD membrane will be OK but I would sure consider a more efficient 75 GPD membrane from Dow when it is time to replace yours.

[sales weasel]

Mine actually claims to be a 125gpd system. That's just over 5gph and I think it's probably making about that much now. I'm going to look for another membrane.
Thanks

[AZDesertRat]

Did you happen to see the manufacturers name on the membrane or package. None of the big three (Dow Filmtec, Applied Membranes and GE Water) makes a 125 GPD membrane.
I am curious as to what they are using with claims like that. I know there is a Chinese company that is dumping some cheap membranes on the market right now.

[sales weasel]

Considering I got the whole unit for $69.99, I'm sure it's cheap filter. I just pulled it out and took a look. It has no brand name that I could see but it does say made in USA and 125GPD.

Here is the same filter on ebay:
http://cgi.ebay.com/Reef-125GPD-Reverse-Osmosis-Water-Filter-DI-free-5-rpl_W0QQitemZ4398669596QQcategoryZ20684QQcmdZViewItem#RO-F4

[sales weasel]

Rat,
You are the winner! I ordered a 75GPD Filmtec and installed it 15-min ago. w/in 10 min the readings were down to 3PPM. I'm sure after a 1/2 hr flush, I'll be seeing 0 PPM.

Originally posted by AZDesertRat
Unfortunately most of the e-bay vendors use 100 GPD membranes which are only 90% efficient and also require 65 psi to produce anywhere near their rated flow at 77 degrees F. I always recommend a 75 GPD Dow Filmtec membrane which is 98% efficient and produces its rated flow at only 50 psi pressure and 77 degrees. If your water is only in the 40 to 50 TDS range the 100 GPD membrane will be OK but I would sure consider a more efficient 75 GPD membrane from Dow when it is time to replace yours.