Spectrapure DI resin????

[Cammed_02]

Just wondering how many gallons you all are seeing through your system before having to replace the DI resin?

I have had a BRAND NEW DI resin in my 90 spectrapure rodi system for about 2 months and make no more than 20 gallons a week. I checked the in line tds meter yesterday and it was reading 2 ppm already.

I called Spectrapure and of course they have every possible explanation, the CO2 is high, the pressure may be too low, the tds going into the membrane is too high(which he retracted once I told him it was only 280ppm), to him saying flat out the DI resin just dosen't last that long.

So how much truth is there to "the DI just dosen't last as long". I would have hoped it would last longer than 160 gallons!

[rrasco]

The DI I got from BFS that came with my kit just started reading 2ppm and I must have made at least 500 gallons. I really don't know how much I made, that's kind of a rough guesstimate. It was certainly more than 160 though.

[Big_Pun]

if you used it weekly to make lil batches it wont last long. when you first turn it on the water coming out for first couple min is very dirty coming out membrane then it slowly lowers and settles in(TDS creep). what I do is put a bypass val e that allows me to purge the system into a bucket while I watch the TDS drop on my system once it's coming out at 5-7 in the meter I know I can start letting into the DI resin and into my 55g drum. making big batches helps me get the most out of it. also water pressure, TDS of incoming water, filter temp, water temp and lots of other factors play role on filter efficiency.

[Cammed_02]

Pressure is good at 75 psi and I do make big (for my systems) batches once a week. I will have to try bypassing the DI until all the tds creep is out and see if that helps. I just expected greater longevity than 160 gallons.

Do the spectrapure 90 gph systems have a DI resin thats refillable?

[BuckeyeHydro]

Cammed - what is the TDS of your RO (not DI) water?

DIresin does have a finite life. Think first about the TDS of the water you feed the DI, and the number of gallons. That concept will explain a lot of what you're seeing.

From there, think about:
Do you have CO2 in your water that's consuming your DI capacity?
Are you feeding water to your DI from a pressure tank?
Are you short cycling your RODI system (frequent on/off like you'd see if your system feeds a float valve in your sump)
Do you have chloramine in your water?

Russ

[Cammed_02]

I don't short cycle, I only make water on sundays and I make the entire 10-15 gallons with no stops. What I will start doing is running the water for about 10 mins without having it go through the Di resin.

The TDS going in is 280 and coming out of the membrane (ro water) is 12, which calculates to a rejection rate of less than 96%. From my understanding it supposed to be about 97-98 % and the DI resin is supposed to take it the rest of the way.

When I told spectrapure about a possible faulty membrane, I have only had the unit for 11 months, they said while the 12 TDS isn't good its not enough to warrant a replacement membrane.

[BuckeyeHydro]

10 minutes is probably overkill on your start up. Here's some data showing permeate TDS in the seconds following two separate start ups - your situation might be a tad different:
http://i224.photobucket.com/albums/dd293/BuckeyeFS/TDSCreep.jpg

96% isn't ideal, but it's not bad and certainly isn't unusual.

Russ

[Cammed_02]

appreciate that, looks like about 2 mins and the pipes should be clear.

[BuckeyeHydro]

That's a good bet - just use your TDS meter to make sure your numbers follow a pattern similar to what I posted above.

[Big_Pun]

thanks Russ your always able to help with our filter questions.

[alton]

Back in 2003 I was getting about the same results 100 to 160 gallons before the DI was used up. Richard from CB Pets on the other hand who was using the same DI resin was getting 800+. Today mine last much longer because my water district is getting its water from a different source. What was in it then and why you are having the same issue today I am not sure of?

[Cammed_02]

Yea that's what the rep told me, he gets about 800 gallons before the resin is toast. Can I just buy some or the re-fillable resin or do I have to buy the whole spectrapure cartrige?


Back in 2003 I was getting about the same results 100 to 160 gallons before the DI was used up. Richard from CB Pets on the other hand who was using the same DI resin was getting 800+. Today mine last much longer because my water district is getting its water from a different source. What was in it then and why you are having the same issue today I am not sure of?

[BuckeyeHydro]

Look to see if one end of the DI cartridge unscrews. If it does, then it's refillable. I believe all/most Spectrapure DI carts are refillable.

Russ

[alton]

Look to see if one end of the DI cartridge unscrews. If it does, then it's refillable. I believe all/most Spectrapure DI carts are refillable.

Russ

I found that out on the ones I had. And it probably would not hurt to try a different brand, you never know?

[Cammed_02]

I'll check it out and get that ordered today Russ.