rodi help

[pizzaguy]

I have the extreme typhoon ro unit. I replaced Di resin yesterday. Made 85 gallons of water Di already exhausted reading 8 tds and color all gone. I never had these issues with my other ro units from two filter guys. Any suggestions would be appreciated

[howaboutme]

Didn't you have this problem not too long ago? Don't worry about the color, that's not a good representation of DI life but that 8 is not good. Did you take that right after having the unit off for a while? Just want to make sure that's not TDS creep. If you did, run the unit for a minute or two and then measure TDS. What's your TDS after the RO (before the DI)? Your RO is the meat of the unit and takes away most of the TDS. If the RO doesn't have a good rejection rate, your DI may not make up the difference regardless of life.

[pizzaguy]

I did but it's getting worse. I replaced all resin turned the unit on ran exactly 85 gallons. When I went to shut it off after the 85 gallons it already had 8 tds.

[pizzaguy]

It's the dual tds version. First meter is usually around 60

[HgrReefs]

Any kind of smell to the water, either outlet or filtered side?

[pizzaguy]

No smell at all.

[zygote2k]

get another tds meter

[HgrReefs]

When were the filters last changed? Not DI, but sediment, carbon and the membrane itself? 60 seems pretty high coming out of the membrane and going into the DI. Mine hovers around 4-7

[howaboutme]

Sediment and carbon don't affect TDS.

 

60 does seem high but what is the TDS of your tap? Rejection rate should be mid 90% ....differs depending on who you ask but it should be around 10 to 15 TDS based on our water in the local area. You need a new RO if your TDS is right. How old is your RO? I know you do large water changes so you may not get the same life as others would get.

 

Edit...Fairfax cty is in the low 300s if I remember correctly.

Edited May 7, 2014 by howaboutme

[pizzaguy]

Less then a year old unit.havent changed filters yet but keep in mind this Di thing has been a problem since day 1 it's only getting worse. I thought the first meter reading was the tds of the tap coming in??

[pizzaguy]

I'll try to find the hand held tds meter that came with the unit and test my tap water shortly. Gotta change 85 gallons first lol nitrates are still through the roof.

[pizzaguy]

Tap water tds is 280

[howaboutme]

I wouldn't use age as a way to judge whether you've exhausted your RO or DI. A TDS meter is the only sure fire way. The carbon and sediment filters should be exchanged on average 6 months, probably more often for you since you've been doing those huge 50G and more water changes and less for someone like me. Keeping those up to date and using a low (1 or less) micron filter will help prolong your RO membrane. I agree that the DI is suspect as a new DI should be able to get your 0, 1, 2, probably less than 5 TDS even from a 60 TDS water after your RO. The DI will just not last very long and maybe that's it? Hard to tell.

 

If your 60 TDS is tap, that's extraordinary. I highly doubt it. If you're on well, it should be sky high, maybe in the high 500s in TDS unless you have a pre-filter system.

 

I'd work backwards first. If you haven't changed your carbon and sediment in a year, they definitely need to be changed. Then if your RO rejection rate ((TDS of tap - TDS after RO) divided by TDS of tap x 100) is not in the mid or low 90s, that needs to be changed as well. After that, you can check your TDS and see if your new DI will get your 0 TDS. Only after that will I be worried about the DI.

[howaboutme]

Tap water tds is 280

 

That sounds right for NOVA. Your RO is shot. Replace that first (carbon and sediment too if they are a year old). Then we can figure out DI issues.

[zygote2k]

I get 114 TDS on tap water in Fairfax near the courthouse as of Monday. Dc is really bad and often runs in the 200's but I've never seen anywhere that is getting 300+.

Don't see how the claim that carbon and prefilter don't affect TDS as they both filter out small particles (solids) that are dissolved in the water.

Carbon and prefilters get exhausted at different rates in different areas and depending on the micron size. 6 months might be good for some places and others may last a year.

Prefilter cartridges are cheap like a few dollars- I'd recommend that you change these when they turn brown. If you really want to know exactly what's going on, you need a TDS reading at the tap, one after the carbon and prefilter, one after the membrane, and one out of the DI. This should pinpoint the problem.

Membranes should last several thousand gallons, DI lasts about 500g, prefilter and carbon might see 300g.

[howaboutme]

I'm in Centreville and get 300.

 

TDS= Total dissolved solids, that's key when you read this (just 1 source):

 

http://www.airwaterice.com/category/z.1/

See middle of the page.

 

 

[pizzaguy]

Ok so 85 gallons last night. Just started to make some more and it's now 70 tds finished product and that's verified with a second hand held meter. I'm gonna order up some replacement filters but again I never had any of these issues with other ro units. I would change Di every 3 or 4 months. Now as you can see its not even 100 gallons. I'm Def not sold on these units

[GraffitiSpotCorals]

Make sure you have the correct flow restrictor on there. I ordered a unit inline which came with the wrong one. Spent a ton of money and time trying to figure out what was wrong.

And you have something wrong going on.

[howaboutme]

Eric..there are so many different possible reasons and I think changing your RO, carbon and sediment is step 1. Then we can narrow it down further.

 

For the DI, are you packing the resin in yourself or are you buying pre-packed DI? If you are packing it in, it needs to be super tightly packed or else the DI won't work well.

 

But yeah, something is fishy. Buy another brand this time as another safety valve, although I believe most, if not all, RO's are the Dow Filtecs....also buy 1 micron or less carbon and sediment filters (assuming you have 2 stage prefilters). Don't get sucked in buying 5 micron filters. Your RO will last longer this way (and you'll get rid of chloramines at the same time).

[pizzaguy]

So should I order a filter kit from awi if so which one would you try

[pizzaguy]

I do pack the rising very tight

[pizzaguy]

Resin

[howaboutme]

If getting from AWI, buy this:

The 1 micron version:

http://www.airwaterice.com/product/PP10/Sediment-Filter-10.html

The 1 micron version:

http://www.airwaterice.com/product/GEM10/Gem-Carbon-Block-Filter.html

 

However...MD is having a sale (15% off coupon code) on their RO products..I just ordered some w/ this special just now actually. They sell .5 micron filters, which are even better.

 

For the DI, how are you storing the bulk resin? It needs to be air tight as CO2 infiltration will negatively affect it's ability to bind ions.

[YHSublime]

I would give AWI a call. They have the best customer service I have ever dealt with, and if you gave them a chance to hear your problem, I fully expect they would troubleshoot with you, and hopefully come up with a solution.

[Der ABT]

whats your pressure going into the RO membrane, if your filters are clogged and you have little pressure going in...that could teh culpret