DI cartridge refilling Q's.

[caferacermike]

I'm replacing the DI resin in a twist off cartridge. I've emptied the old resin. Any tips or tricks that I should do before or during refilling? How much media shall I use in each cartridge? I prolly shouldn't rinse the media right? Figures it would "use up" some it's absorbing properties. How about the foam? Clean it or run it? To clean it would Ijust put a few drops of bleach in a cup with plenty of water and let it soak?

Found out my 300GPD unit had a torn membrane. I bypassed that cartridge and have it set up as a 200GPD unit until these membranes are toast, then I'll bring it all back online as a 300. I have 2 DI cartridges I'll be refilling. What I noticed was that my RO used to read 54 and my DI read 4 or so. Now that I have my RO corrected I get about 2-3 out of the membranes and about 12 out of my DI. I figures my DI is spent. But I'm confused since I wouldn't think I'd get dirtier water then I put in, unless the DI was really dirty. Eh.

[thedude]

DI resin when spent does leach back into your water. That's the reason you're seeing an increase in TDS.

Glad to hear that the two RO membranes are working properly. Is the waste ratio better?

John

[caferacermike]

Found the refill advice on Buckeye. Brian do you "pack" your resin? They say to do that on their site. I did until I could barely fit the sponge back in. 0TDS woohooo. All I need now is 2 50g barrels. One for waste and one for "clean". I plan to use the waste to do water changes in the freshwater tanks around the house instead of sending it down the drain. The TDS says it's 2TDS, uhm that's way better then the 286 going in from the tap. Right now it really sucks waiting 40 minutes to fill up a 5g jug. lol.

[JimD]

You want to pack it just enough to prevent channeling. Two or three light taps should do it. If you contact Russ at Buckeye, he should be able to tell you the weight of a properly filled cartridge.

[caferacermike]

3 taps was what I went with. Filled it to 3/4 of an inch to the top, compressed the sponge 1/4". John your post came up while I was replying. Since I have the restrictor for the 300 in it right now I was still getting a bit more waste then I should. Since I now know for fact the restrictor was missing, I used to jugs and timed the ouput. Using an inline valve I throttled it back until my ratios were about 3-1. Took about an hour of fiddling but I got it set doing it like that. My waste is about 2 and my clean is 0.

[BuckeyeHydro]

From our FAQ's:

Is there a right way and a wrong way to load a refillable cartridge with replacement DI resin?
Yes! Seems like this would be a simple matter of unscrewing the bottom of the cartridge, dumping the old resin in the trash, placing fresh resin in the cartridge, and replacing the cartridge in the housing. Well, almost...

It's how you place the new resin in the cartridge that's important here. First a little background on DI resins.

Remember that the vast majority of folks in this hobby who use DI resin take advantage of mixed bed resin. This resin is composed of small plastic cation beads and anion beads that remove positively charged, and negatively charged ions, respectively. These beads work most effectively when they are thoroughly mixed (which is the way they are when you buy them).

To assure the beads stay mixed together, pack the beads tightly in the refillable cartridge. Fill the cartridge to within a 1/4 inch of full with resin. Now pack the resin by dropping the cartridge repeatedly (~40 times), rubber washer end down, on a hard surface from a height of about 1/2 inch. Essentially what you are doing is bouncing the cartridge to get the resin to settle. You'll see that it settles significantly. Add more resin and settle it again. You'll not see as much settling this time. Now fill the cartridge a third time to within 1/8 inch of the top and pack the resin a third time. If you see any settling at all, refill to within 1/8 inch of the top, replace the cap, and you're good to go! Packed in this way, you'll not see the resin separate over time.

[beareef19]

where do you guys get your resin to refill your cartridge and what is the average waste you get on your systems per gallon of good water/
Barry

[JimD]

I get mine from either Buckeye or Coralreefbazaare. My ratio of good to bad is right at 3:1.

[caferacermike]

After a lot of work mine is now workign at 3:1. I was missing my restrictor. I'd recomend Buckeye for resin as they are the nicest retailer of the stuff I think I've ever seen.

[beareef19]

OK just did a test 3/4 gal at 13tds with 5gal waist in approx 40min at this rate I will never get the 75gpd that it is rated at any recomendations.
Barry

[BuckeyeHydro]

OK just did a test 3/4 gal at 13tds with 5gal waist in approx 40min at this rate I will never get the 75gpd that it is rated at any recomendations.
Barry

0.75 gallons in 40 minutes equates to about 24 gallons per day.

If you have a Filmtec membrane they should reach their rated capacity with feed water at 77 degrees F and 50 psi (with 250 ppm feed water). Other manufacturers require more pressure. Colder temperatures and lower pressure will decrease the production of permeate. This lack of production is also one of the symptoms of a bad membrane.

Russ @ BFS

[beareef19]

I dont have a pressure guage so Im not sure what it is but I do have a new membrain so I will change that and see if it helps . How often should the cartridge be changed? and also the resin. Thanks
Barry

[BuckeyeHydro]

I dont have a pressure guage so Im not sure what it is but I do have a new membrain so I will change that and see if it helps . How often should the cartridge be changed? and also the resin. Thanks
Barry

A good rule of thumb is to replace your sediment filter and carbon block after six months. A more precise way to maximize the useable 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. The Matrikx+1 (“Chlorine Guzzler”) for example will remove 99% of chlorine from 20,000 gallons of tap water presented at 1 gpm. Original equipment suppliers commonly provide carbon cartridges rated at 2,000 to 6,000 gallons.

Regarding your RO membrane and DI resin, use your TDS meter to measure, record, and track the tds (expressed in parts per million) in three places:
1. Tap water
2. After the RO but before the DI
3. After the DI.

The TDS in your tap water will likely range from about 50 ppm to upwards of 1000 parts per million (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 filter (collectively called prefilters) 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 its 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 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 less purified water (aka “permeate”), but have a higher rejection rate (96 to 98%). The life span of a RO membrane is dependant 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 total dissolved solids (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 less water as their function declines.

After the RO membrane, water will flow to your DI housing. DI resin in good condition will reduce the 40 ppm water down to 0 or 1 ppm. When the DI output starts creeping up from 0 or 1 ppm to 3 ppm, 5 ppm, and higher, 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 then would otherwise have been the case. Sometimes the problem is poor quality resin – remember that all resins are not created equal!