RO/DI Needs New Membranes Already???

[Kearnel]

I recently installed a Spectrapure 4 stage unit, it's no more than 3 or 4 weeks old. It's the newer unit with the 3 probe TDS meter and manual flush. Last night I made a new 5 gallon bucket of water and noticed that the DI stage was at 001 and not dropping. I let it run for awhile hoping it would go to all 000 but NOPE. Today it's at 002. This can't be, there's no way I have to buy a $70 membrane every month, I bought this thing so I wouldn't have to spend the money at a water store. It's always been slow to come to all 0 but it always did..........eventually. The first probe reads 320, the second reads around 7 so they are normal and unchanged. Is my water really that bad that it's going to cost that much to make it clean because if that's the case I simply cannot go on using this or any other ro system. Any ideas what could be, is it really worn out after making less than 50 gallons of water.

[ca1ore]

It's the DI resin that had been depleted; RO membrane is fine. I get about 300 gallons out of a charge of resin (around $12 USD; probably $50 CDN ). Only 50 gallons is a bit low though, even for a DI cartridge processing 7 TDS. Are you on a well; what's your water pressure?

[Kearnel]

Its city water and the pressure is about 80, it just gets weirder. Not content to just leave things alone I removed all the canisters and reinstalled. The ball valve for manual flush was leaking so I swapped it out for a spare I had that came with the unit. In the process of pulling the lines out water shot out all over the place and yes I did turn the water off. I hooked everything back up and am now getting 000 on both the second and third probe, the first dropped down to 277 ppm. Could something have been causing a bad reading that got flushed out when I got the purest shower ever.

[Kearnel]

I just saw your little money quip, I'll let you have that one because its only sometimes true.

[Kearnel]

Now it's back to reading 389 on probe 1, 11 on probe 2 and 3 ppm on probe 3. This thing makes no sense.

[Buckeye Hydro]

You're getting 97% rejection from your membrane, so that's pretty reasonable.

With your RO water at 11, you should see about 500 gallons from a standard-sized (10" x 2.5" nominal) DI cartridge. You're saying you only got less than 10% of that, so somethig is wrong.

Let me ask a few questions to see if we can figure this out.

Is this color-changing resin?
If so, at you seeing any color change?
If so, is it at the top, or the bottom of the cartridge?

Russ

[Kearnel]

Nothing on any part of the manual says colour changing resin but I do notice a white colour on the bottom of the cartridge, it's about 1/4 inch or so but other than that it's it's brownish colour. It's production has remained the same as well.

[Buckeye Hydro]

You are probable seeing the white sponge inside the DI cartridge.

Do you have chloramine in your water?

[Buckeye Hydro]

Are the three probes twisted correctly in the fittings?

[Kearnel]

I believe there is chloramine in the water, the water source in this city is pretty nasty. As far as the probes go, I'm not sure, the unit was all assembled so I just screwed it to the wall, went through the initial setup and started using it. I always found something a little off with it because like I've said, it took it a rather lengthy amount of time to fall to 000 on start up each time. I've been reading other posts, some people use the unit for water then open the flush valve and turn the water source off until next use. I don't do that since I have a reservoir with a float valve. Could having the unit under pressure constantly have caused any issues? I do flush for at least 30 seconds before and after each fill. I can't check the probes because I'm at work but will tonight.

[Buckeye Hydro]

Constantly being under pressure is not the issue.

TDS Creep is the cause of the high TDS on start up - that is not unusual.

If you have chloramines, and if your system short-cycles (frequently kicks on for short periods), that would certainly be contributing to what you are seeing.

Russ

[Buckeye Hydro]

Email us if you'd like a copy of the instructions for your TRM1 TDS meter.

Russ

[Tigerdragon]

Are you setup to keep your resevoir constantly topped off? I used to do this and found even with the auto shutoff and check valves all properly installed i would kill my di resin very fast in a month or less. Got a bigger ato tank installed a float valve in it so i wouldnt overfill and have a flood and only turn on my ro unit when i need to fill it or i need to make water otherwise it is off. My resin now lasts a whole lot longer. Even with all the shutoffs and such i found that having the unit on constantly would deplete resin.

[Kearnel]

It doesn't really kick on for short cycles, it's really only when I do a water change, 5 gallons is all I do twice a week plus whatever water I add to compensate for evaporation. I copy of the instructions would be good to have, which email to I send to.

[Buckeye Hydro]

Tiger - Your issue was "short-cycling." Your system was frequently kicking on and staying on for only a short period of time.

[Buckeye Hydro]

Originally Posted by Kearnel

It doesn't really kick on for short cycles, it's really only when I do a water change, 5 gallons is all I do twice a week plus whatever water I add to compensate for evaporation. I copy of the instructions would be good to have, which email to I send to.

Info@BuckeyeHydro.com

[Buckeye Hydro]

High CO2 could be another cause of your short resin life.

[Buckeye Hydro]

Originally Posted by Kearnel

It doesn't really kick on for short cycles, it's really only when I do a water change, 5 gallons is all I do twice a week plus whatever water I add to compensate for evaporation. I copy of the instructions would be good to have, which email to I send to.

How about everytime you evaporate 1/4" of water from your reservoir?

[Kearnel]

I suppose evap from the reservoir is possible, it's covered so it's not really directly exposed to open air but I also don't sit beside it all day so truthfully, I have no way of knowing if it comes on in little bursts or not. I'd have to say it doesn't because you have to take out a fair amount of water just to get the float valve to open.

[Vinny Kreyling]

If possible top off from a larger vat or garbage can, say 30 gallons, run it low & fill it up again. The longer the unit runs the better the expected life of the membrane.

[Kearnel]

I see what yous are saying, I figured that running 5 gallons at a time would be sufficient but I guess not. I suppose my best bet is to replace the DI filter and try it in larger amounts. I believe my reservoir is 25 gallons so I'll try using it all up then let it refill. Hopefully that will help prolong the life of the cartridges.

[Vinny Kreyling]

Sounds like a plan.

[slief]

Here is the water quality report for you area. Your report isn't terribly inciteful. The reports out here have a lot more info in them. It doesn't look like you have chloramines in your water but you do have chlorine although your levels aren't much different than mine. Perhaps Russ could shed some more light on your report because I am no expert when it comes to stuff in water that degrades our cartridges other than knowing that Co2, chlorine and chloramines are bad..
http://www.brantford.ca/Water%20Qual...20December.pdf

One contributing factor in cartridge life is your short runs. Running 5 gallons at a time isn't ideal and can really shorten the cartridge life. Co2 in the water can play another roll in decreased cartridge life. Not flushing your cartridges doesn't help either but you need a flush setup to do that.

My water quality is not good (475+ TDS with all kinds of stuff in it) but I get nearly 1000 gallons out of my first stage SpectraPure MaxCap DI cartridges and even more out of the second stage and this is at a 1:1 ratio. Granted my RODI has an auto flush that flushes with DI water and not tap water but I make a point of limiting my water making runs to no less than 30 gallons. The longer the run, the better. Upgrading your membrane to the 99% rejection membrane would help a bit as well. If it's at all possible to make your water making runs significantly larger, that would probably go a long way in increasing your cartridge life.

[Kearnel]

How the heck do you's find those water reports like that, I tried but just got some jargon that requires a masters in something to decode that nonsense. My unit does have the manual flush and I am pretty good at doing it before and after each use and if I'm not mistaken it also comes with the 99% rejection cartridge.

[slief]

Originally Posted by Kearnel

How the heck do you's find those water reports like that, I tried but just got some jargon that requires a masters in something to decode that nonsense. My unit does have the manual flush and I am pretty good at doing it before and after each use and if I'm not mistaken it also comes with the 99% rejection cartridge.

Pretty much every water district in North America publishes that data. A google search for "Brantford, Ontario Tap Water Quality Report" or "Brantford, Ontario Water Quality Report" or "Brantford, Ontario drinking Water Quality Report" would yield the same info. Same goes for virtually any other city across the country.

That said, flushing is very important but short runs like that are not good and shorten the cartridge life. I think this is because the cartridges see so much time with elevated TDS before they get a chance to settle and don't end up getting enough run time with lowered TDS. I'd double check to see if your unit came with the 99% rejection membrane. It may have but I'm not sure. If it is 97% rejection, then I think your outgoing RO TDS should be closer to 5 or 6. I typically see 6-7 with my 475 TDS water. Then again, depending on what is in your water, that will impact RO membrane life and your RO TDS although I would not expect you to have exhausted your RO membrane so soon nor does it sound like it is. That said, I am no expert on RODI's. I only know what I know from my experience with mine and those that I have setup for friends and my conversations with Spectrapure.