New RO/DI filters reading 800 on TDS??

[Hellion179]

Need some trouble shooting here please. I am replacing the filters on my several year old unit. All new filters. I was putting out 250 or so on TDI. It's now reading 790!

So it's a 6 unit filter, i have the DI on a second line and I shut off the last carbon filter and have it run through the DI instead. I ran 10 gallons through it and tossed them. The water comes out VERY VERY Fast. It takes about 10 minutes to fill up a 5g bucket. Maybe less time.

I bought an upgrade from purewaterclub to increase production from 150-300 gpd. It's a small little white piece that goes in the waste line. The old one said 450, this one says 600.

Any advice for me?

[Jamey1010]

The white piece is the flow restrictor, you want 4 gallons waste water to 1 gallon product water.

You have essentially just added a second 150 gpd membrane to get twice as much water in the same amount of time and it's probably high because the flow rate isn't correct.

150 gpd day membranes are usually only rated at 90% rejection so there not the best choice if you have really high tds to begin with and I'm not a big fan of purewaterclub products

[Hellion179]

I've been away from the RO/DI system for awhile. When I purchased from them before I thought they were more of a go to place for savings(not for a cheap product).

So, should I just replace that flow restrictor?? Or what do you suggest?

Thanks for the response.

The water is actually reading worse than my tap water, lol. How can that be?

[Jamey1010]

You have to check the 4:1 ratio and those style flow restrictors are not adjustable just preset.

There's better places now days, BRS, Spectrapure, buckeye field supply, filter guys to name a few...

[Hellion179]

I'm beginning to think I have setup wrong somewhere...The water is still flying out of there despite the change in restrictor. Gonna have to find a diagram that shows proper setup..should have taken pictures first....

[Dazedman00]

Take some pictures. It sounds like you have it assembled incorrectly. Your flow should be trickle to drips depending on GPD membrane.

Also anything 75GPD or over should have at least 60psi for best results.

I also strongly recommend Buckeye Field Supply. Great products and great prices. They will not do you wrong.

[Hellion179]

It was setup incorrectly :*( there was no label on the new RO housing(it came with the "upgrade). I set it up int he same position as the old one, but internally they were different. it's now trickling.

The first little sample I got was 500, which is a lot better than 900..and it wreaks of something..epoxy maybe? i don't remember all these smells, lol.

I'll let it run 5g then I'll recheck it and go from there. If I'm still having issues I'll post some pictures.

Thanks guys.

[Dazedman00]

If you are still getting smells I would be concerned with the quality/state of the membrane. By putting it in backwards you just back flushed it and forced anything that's was in it out. Which is probably a moisture agent to keep the membrane safe while sitting on a shelf waiting to be sold.

I sure you will be good after 5g of water is made.

[Hellion179]

Originally Posted by Dazedman00

If you are still getting smells I would be concerned with the quality/state of the membrane. By putting it in backwards you just back flushed it and forced anything that's was in it out. Which is probably a moisture agent to keep the membrane safe while sitting on a shelf waiting to be sold.

I sure you will be good after 5g of water is made.

I had the membrane in correctly. It was the lines I had wrong. The grey water was going into my collection container and my clean water was going into my sink. Just switched the lines at the end of the unit and voila..now my waters going where it's supposed to.

1g down and it's at 15 right now.

Speaking of TDS meters..now that i have one, what is the recommended range for changing your filters? My local tap has 600 or so bugs in it.

[Dazedman00]

That will do it. The grey water is pretty nasty.

I change mine every 6-10 months. I also keep a log of how much water I make and always round to the next gallon. This way I have a semi accurate log. I have only had a few times that I didn't need to change my filter, carbon block, GAC and resin by the 10 month point.

[Buckeye Hydro]

A "600" flow restrictor should be teamed with a single 75 gpd membrane - with conditions close to factory spec you'd get about a 4 to 1.

[Buckeye Hydro]

Originally Posted by Hellion179

Speaking of TDS meters..now that i have one, what is the recommended range for changing your filters? My local tap has 600 or so bugs in it.

A good rule of thumb is to replace your sediment filter and carbon block after six months. A more precise way to maximize the usable life of these two filters is to use a pressure gauge to identify when pressure reaching the membrane starts to decline. This is your indication one or both of the filters is beginning to clog.

Also be cognizant of the chlorine capacity of the carbon block. A good 0.5 micron carbon block for example will remove 99% of the chlorine from 20,000 gallons of tap water presented at 1 gpm. Some original equipment suppliers commonly provide carbon cartridges rated at 2,000 to 6,000 gallons. Remember that all the water you process, both waste water and purified water, go through the carbon block.

Regarding your RO membrane and DI resin, use your total dissolved solids (TDS) meter to measure, record, and track the TDS (expressed in parts per million [ppm]) in three places: 1) tap water, 2) after the RO but before the DI, and 3) after the DI.

The TDS in your tap water will likely range from about 50 ppm to upwards of 1000 ppm. Common readings are 100 to 400 ppm. So for sake of discussion, let's say your tap water reads 400 ppm. That means that for every million parts of water, you have 400 parts of dissolved solids. How do we go about getting that TDS reading down to somewhere near zero?

If you do some experimenting with your TDS meter, you'll note that your sediment filter and carbon block (collectively called “prefilters” because the treat the water before it reaches the membrane) do very little to remove dissolved solids. So with your tap water at 400 ppm, you can measure the water at the “in” port on your RO housing and you'll see it is still approximately 400 ppm.

The RO membrane is really the workhorse of the system. It removes most of the TDS, some membranes to a greater extent than others. For instance, 100 gpd Filmtec membranes have a rejection rate of 90% (i.e., they reject 90% of the dissolved solids in the feed water). So the purified water coming from your 100 gpd membrane would be about 40 ppm (a 90% reduction). Filmtec 75 gpd (and below) membranes produce purified water (a.k.a. “permeate”) more slowly, but have a higher rejection rate (96 to 98%). The lifespan of a RO membrane is dependent upon how much water you run through it, and how dirty the water is. Membranes can function well for a year, two years, or more. To test the membrane, measure the TDS in the water coming in to the membrane, and in the purified water (permeate) produced by the membrane. Compare that to the membrane’s advertised rejection rate, and to the same reading you recorded when the membrane was new. Membranes also commonly produce purified water more slowly as their function declines.

After the RO membrane, water will flow to your DI housing. DI resin in good condition will reduce the TDS in the RO water down to 0 or 1 ppm. When the DI output starts creeping up from 0 or 1 ppm, you know that your resin needs to be replaced. Sometimes people complain that their DI resin didn't last very long. Often the culprit is a malfunctioning RO membrane sending the DI resin “dirty” water. This will exhaust the resin quicker than would otherwise have been the case. Sometimes the problem is poor quality resin – remember that all resins are not created equal.

Additionally, don’t forget to sanitize the entire system at least once per year, and wash and lube your housing o-rings with food-grade silicone grease every filter change.

Russ