Reefs.org Forums

[Ben]

Does DI resin go bad? What if it drys out?

I just replaced my DI resin and only got 20 gal before my TDS was 7. I am gonna check before and after RO when I get home but seemed dry when I filled my cartridge. Does it go bad?

[ANEMONEBUFF]

My understanding is that the resin needs to stay wet to work. You could email BRS. I am sure they have an answer.

[Ben]

I think it was a membrane issue, although I think the dry resin exhausted faster then wet resin would have, my tap TDS 147 and post RO was 15 so I am not getting the 99% rejection ratio I should be. Its a new unit and that's what they advertise at least.

[rbursek]

A new RO membrane usually takes about 10gal through it and not let those gallons go to the DI resin. It is to flush out the strorage solution that it is packed in. That may have exhausred your DI faster, I have about 12 TDS's going into my DI and I get about 250gal before it is exhausted. If a RO membrane goes dry then it is rewend, as far as DI resin going dry I have never heard that. With a 99% membrane and 150 inlet TDS your RO outlet TDS should be less then 2.

[Ben]

Thanks for the help.

I wrote to the company to ask about the TDS after the membrane being off and got this reply,

Hello Ben,

I wouldn't be terribly concerned. That after RO reading seems pretty on target, and out of the faucet your water is relatively clean (mine reads in the 300-400 range!). Depending upon the resolution of your TDS monitor, it could be something as simple as it reading a little higher than it actually is. I usually have a similar experience with my setup, and usually my readings start around 0-5 and once I have produced a decent amount it starts reading in the 10-15 range, but usually it isn't time for me to change cartridges until I see it read in the 20-30 range. Just let me know if you have any other questions!

[Ben]

I'm going to email vertex and see what they think.

[hitmanhoos]

Hey Ben, Is this the system you have? http://premiumaquatics.com/store/mercha ... =Vertex-RO

What do you think of it? I'm in the market and can't decide between this Vertex or a BRS system. Do you think the Production to waste water ratio of 1:1.5 is accurate?

Thanks

[rbursek]

Hitman,
Not all but most RO membranes standard of GPD and product to waste ratio is set at 60psi @77*F for supply water, anything lower in any combination will lower GPD and raise the ratio. Of course anything higher or combination will increase GPD and lower the ratio.

[sfsuphysics]

yeah that's silly, who the hell has water that's 77° coming out of the ground!

[rbursek]

Hitman,
I totally agree, I can not figure out why they use that temp for a standard, I would think 60* would be move of an accurate average.

[Ben]

What do you think of it? I'm in the market and can't decide between this Vertex or a BRS system.

I love the unit, at least I loved my original one. I like how everything is top mounted, the computer auto flushes the membrane and booster pump keeps the pressure right. The only problem is the wires attaching the computer to the power supply are just capped with little grey wire caps that slip off easy. That and the computer/power supply has no fuse. The old unit used to give me a ton of water at 0 TDS before I had to change resin. I still haven't heard anything from vertex and refuse to use water with high TDS, so I'm SOL right now.

[dupaboy1992]

When resin get dry, it lose its ability to do its job as ion exchange. So, yes, it does goes bad.

[rbursek]

I was looking for a post from Russ at BRS about resin, but it must be kept sealed or else it can pick up ions from the air and loose its effecientcy. I keep mine in a vacumm sealed bag after opening. He also recommended buying no more then what yu would need for 6 months.

[Ben]

Turns out its cheaper to buy the single bulk refills from BRS anyhow then the bulk larger pack. The large color changing resin pack does 6 refills and is $59.99, while if you buy 5 of the single refill packs of color changing resin its $48, and each refill in individually packed so no worry about any drying out.

FWIW I am still not happy with the rejection rate I am getting, and have heard nothing back from vertex, and premium aquatics seems to think there is nothing wrong with a horrible rejection rate on a new top end RO/DI unit....

[rbursek]

Ben,
here are 2 formulas for checking your RO membrane eficiency, one is easier then then the other but not as accurate, it will be a start.
http://www.buckeyefieldsupply.com/calc.asp
http://www.spectrapure.com/CALC-FORMULA.pdf

[AZDesertRat]

The Vertex units are very poorly engineered and probably won't be around long. Many many vendors and manufacturers have tried the low waste route for years but it just does not work long term. Talk to people like Spectrapure and Air Water & Ice who have been in business 25+ years. They tried it and moved on years ago. Flushing a membrane with tap water containing the very TDS you are trying to flush away is not the answer. It still builds up. Add to that the Vertex I looked at had cheap wire nuts holding the 120v AC wires together on the unit! Thats a lawsuit waiting to happen. Most vendors use 24v DC and shrink tube or pot the connections for safety.

As far as I know, today there is only 1 proven system that really works. The Spectrapure UHE is what the Vertex is trying to imitate but its not the same. The UHE uses stored DI water to both flush the RO membrane and to pickle or store it in when the unit is not in use. The DI pulls the contaminants out so they can be flused away. Yes, its not cheap at $800 but it really works. I own one myself and its been flawless for over 18 months now. My tap water TDS averages 800 but can reach as high as 1200 and as low as 600. I have been making RO/DI for 18 months for two tanks, a 100G reef with a 30G sump and a 16G nano so have made a lot of water in that time. The RO only TDS varies between 5.3 and 6.2 using a handheld COM -100 TDS meter and the RO/DI is still 0 TDS and I'm only on my first replacement DI cartridge. The prefilter and carbon block are original and I am testing PSI drop and chlorine breakthru to monitor their conditions. Since there is no 4:1 waste there is much less passing through them so they last much longer. I am running at 1:1 waste ratio and have gone as low as 0.66 to 1 but didn't gain much in GPD so went back to 1:1. I get over 120 GPD at 90 psi and 100 GPD at 80 psi with the booster pump.

I figure I have saved quiet a bit so far. With a normal unit I would be on my third or fourth set of replacement perfilters and carbons and probably my 10th to 12th replacement DI cartridge or refill since I was getting 150 gallons per DI cartridge before due to my high CO2 in the water and high TDS. Add all those up plus the savings in water and sewer costs and its well on its way to paying for itself.

[Ben]

This is my second one of these vertex units. The first one worked very well for me as far as me getting a lot of water from my DI cartridges and not having to replace my sediment or carbon filters much. It replaced a standard RO/DI I bought from BRS that burnt through all cartridges much much faster then the vertex unit does.

Add to that the Vertex I looked at had cheap wire nuts holding the 120v AC wires together on the unit! Thats a lawsuit waiting to happen. Most vendors use 24v DC and shrink tube or pot the connections for safety.

That's one of my biggest complaints with this thing, the wire nuts don't even fit on the wires properly and fall off.

My tap water TDS averages 800 but can reach as high as 1200 and as low as 600

Ouch that's some nasty water!

[AZDesertRat]

I guess in China or Asia they can get away with wire nuts. It could never pass ANSI/NSF, UPC or UL inspections here.

Short term you won't notice the membrane plugging up, its the long term where it suffers, heck you could run a RO with no waste or flush for a little while if you have fairly low TDS to begin with but it wil lcatch up to you. Good filters and waste ratio can make membranes last 10 years of hard use where low waste would probably last 12 months in the same waters. Like I said all the major players tried and dismissed the low waste years and years ago, they don't want to damage their reputations by selling something that won't last.