WMAS Discussion Forum : DI Resin http://www.utahreefs.com/forum/ Copyright (c) 2006-2013 Web Wiz Forums - All Rights Reserved. Thu, 18 Jun 2026 01:07:54 +0000 Sun, 08 Dec 2013 08:14:00 +0000 http://blogs.law.harvard.edu/tech/rss Web Wiz Forums 12.03 360 www.utahreefs.com/forum/RSS_post_feed.asp?TID=68157 <![CDATA[WMAS Discussion Forum]]> http://www.utahreefs.com/forum/1by1.gif http://www.utahreefs.com/forum/ <![CDATA[DI Resin : I could be wrong but it appears...]]> http://www.utahreefs.com/forum/forum_posts.asp?TID=68157&PID=546433&title=di-resin#546433 Author: Mark Peterson
Subject: 68157
Posted: December 08 2013 at 8:14am

I could be wrong but it appears that the DI resin on Johnny Heavens RO-DI unit is saturated/spent. In fact it may have been spent many months ago. If so, the unit has been producing RO water with a TDS of 3-4 ppm. If this tank is doing well, this leads us to conclude that the DI resin is probably not even needed. I would say it's okay to discard the DI resin and run the unit without DI. The tank is doing just fine with RO water. Smile

If you want to know more of the technical reasons why, read on...

The reason for what is called "TDS creep" is that when the water flow stops through the RO membrane, the equalization of pressure on both sides of the membrane allows a small amount of dissolved solids to slowly pass through the membrane to the pure water side. The hobbyist then has a choice, to flush out that high TDS water or not worry about it because, like I tried to say before, it's just a few TDS that won't hurt in the whole scheme of things because it actually feeds the coral. Smile

My detailed answer to JohnnyHeavens question
Knowing when to change the resin is a matter of monitoring the TDS of the RO/DI water. In normal operation the TDS coming out of the DI stage will be at a baseline of zero ppm. Usually when the DI Resin is saturated the TDS will be noticeably higher. This change is noticeable fairly swiftly, within a week or even a few days. Like I said above, since some people use tap water of 200 TDS, we really needn't fret about a few TDS but when the TDS is rising, that's telling us it's time to check the unit. At this point, while removing the DI resin/chamber, it's a good idea to check the RO water TDS to make sure it is below 10 ppm, or lower if it has been producing better that that.

Thinking about DI resin that has been making 100 gals a week for 13 months suggests two possibilities. Either the RO water is extremely pure, meaning that the RO membrane has almost zero TDS for the DI resin to remove, which greatly extended its life,
OR
the DI resin reached saturation long ago causing the TDS reading to be constant ever since, essentially being RO water.

The last statement in John's post about having to run the unit for a few minutes to discard the 200 ppm TDS water would indicate the latter is the case. DI resin in good condition would normally soak up that initial 200 TDS.

Hope this helps and that my explanation is clear.

Mark Hug
808-345-1049
]]> Sun, 08 Dec 2013 08:14:00 +0000 http://www.utahreefs.com/forum/forum_posts.asp?TID=68157&PID=546433&title=di-resin#546433 <![CDATA[DI Resin : I run a Spectrapure Maxcap 90...]]> http://www.utahreefs.com/forum/forum_posts.asp?TID=68157&PID=546419&title=di-resin#546419 Author: tileman
Subject: 68157
Posted: December 08 2013 at 12:19am

I run a Spectrapure Maxcap 90 double DI  and I try to change out my two resin cartridges twice a year. I also change out my carbon and first stage filter 3-4 times a year.  Anytime my output isn't zero, it's time.]]> Sun, 08 Dec 2013 00:19:53 +0000 http://www.utahreefs.com/forum/forum_posts.asp?TID=68157&PID=546419&title=di-resin#546419 <![CDATA[DI Resin : It was sort of asked but how do...]]> http://www.utahreefs.com/forum/forum_posts.asp?TID=68157&PID=546412&title=di-resin#546412 Author: JohnnyHeavens
Subject: 68157
Posted: December 07 2013 at 11:06pm

It was sort of asked but how do you determine when to change the resin? I've thinking about it and I make well over 100g a month and I've not had to change out my DI resin in 13 months now. I'm in west Riverton and inbound TDS is in the 300 range. Most often it's 260-310 inbound and I'm still 3-4 TDS on the outbound product. Even after the above usage and the setup of two decent sized systems of 150g or greater. 

I do have to run my RO for about 10 minutes after letting the system sit for a day or so. I try to do larger batches of water and if I just run the unit, the product water has a TDS of about 200. It comes down to the 3-4 over the next 10 minutes or so.

  
]]> Sat, 07 Dec 2013 23:06:32 +0000 http://www.utahreefs.com/forum/forum_posts.asp?TID=68157&PID=546412&title=di-resin#546412 <![CDATA[DI Resin : Mark Peterson wrote:Yesterday,...]]> http://www.utahreefs.com/forum/forum_posts.asp?TID=68157&PID=546407&title=di-resin#546407 Author: JohnnyHeavens
Subject: 68157
Posted: December 07 2013 at 10:35pm

Originally posted by Mark Peterson Mark Peterson wrote:

Yesterday, I visited a hobbyist here in Murray that uses conditioned tap water. His tanks are awesome and all coral, including his SPS dominant tank, have been growing like crazy. This confirmed my long held belief that we need not get worried over a few TDS in our purified water.

I don't want to be a pessimist here Mark but does this actually confirm anything helpful? Aside from some random hobbyist in murray growing some unknown corals. Do you know what's in my water? I don't. Thus, it seems prudent to clean the water and mix it to known parameters rather than just hope for the best. Even if I test my water and somehow only leave the Alk/Calcium that I want, we have no way to know or any reason to suspect that my water will stay of a constant make up. My inbound TDS is all over the place and somehow I doubt this variance is Riverton City adjusting things for the benefit of my aquaria. It seems unhelpful to suggest that any ol' tap water will do. 

When handed a gun it is standard practice to check the chamber. Even if someone says it's unloaded, you check. Water for our aquariums isn't much different. Isn't it safer to just make sure it's good and safe? 
]]> Sat, 07 Dec 2013 22:35:16 +0000 http://www.utahreefs.com/forum/forum_posts.asp?TID=68157&PID=546407&title=di-resin#546407 <![CDATA[DI Resin : Yesterday, I visited a hobbyist...]]> http://www.utahreefs.com/forum/forum_posts.asp?TID=68157&PID=546318&title=di-resin#546318 Author: Mark Peterson
Subject: 68157
Posted: December 07 2013 at 9:01am

Yesterday, I visited a hobbyist here in Murray that uses conditioned tap water. His tanks are awesome and all coral, including his SPS dominant tank, have been growing like crazy. This confirmed my long held belief that we need not get worried over a few TDS in our purified water.

Years ago, I set up a tank for a friend using the Kold-Steril water filtration system as seen here http://www.marinedepot.com/Poly_Bio_Marine-PB-vd.html This filtration removes any harmful compounds but leaves Alkalinity, Calcium and Magnesium in the product water (Alkalinity and Calcium make up a good portion of the TDS in tap water). His tank always looked awesome and he kept some animals that had been difficult for other hobbyists. Supplements were almost unheard of for this guy.

Just FWIW.

Aloha,
Mark Hug
808-345-1049
]]> Sat, 07 Dec 2013 09:01:25 +0000 http://www.utahreefs.com/forum/forum_posts.asp?TID=68157&PID=546318&title=di-resin#546318 <![CDATA[DI Resin : Ahh, I just looked it up. The...]]> http://www.utahreefs.com/forum/forum_posts.asp?TID=68157&PID=546312&title=di-resin#546312 Author: ReefdUp
Subject: 68157
Posted: December 07 2013 at 8:04am

Ahh, I just looked it up. The EPA secondary drinking water regulations is 500...meaning it's unenforceable. Wow...1000...that's hard to swallow (ha...haha......)]]> Sat, 07 Dec 2013 08:04:57 +0000 http://www.utahreefs.com/forum/forum_posts.asp?TID=68157&PID=546312&title=di-resin#546312 <![CDATA[DI Resin : ReefdUp wrote:700 is above...]]> http://www.utahreefs.com/forum/forum_posts.asp?TID=68157&PID=546213&title=di-resin#546213 Author: 08TRDOFFROAD
Subject: 68157
Posted: December 06 2013 at 10:11am

Originally posted by ReefdUp ReefdUp wrote:

700 is above the EPA limit for city waterif I remember correctly.


According to the city water report we get annually, 1000 TDS is the cut off. If the water supply has a TDS of 1000 or more, the city has to prove that no access to better water exists. Herriman's water is ridiculously hard as well. 7-8 grains is considered hard, ours tested at 28 grains.
]]> Fri, 06 Dec 2013 10:11:11 +0000 http://www.utahreefs.com/forum/forum_posts.asp?TID=68157&PID=546213&title=di-resin#546213 <![CDATA[DI Resin : Aaron I am running the same unit...]]> http://www.utahreefs.com/forum/forum_posts.asp?TID=68157&PID=546082&title=di-resin#546082 Author: Krazie4Acans
Subject: 68157
Posted: December 05 2013 at 1:40pm

Aaron I am running the same unit as you. My TDS in is 278-280. Out of the membrane is 6-10 and out of my single stage DI is 0. I only use about 20 gallons per week and I am going on almost 12 months with only changing the sediment cartridge once. Yours should be doing almost the same thing.

It sounds like your back pressure shutoff isn't working and even though your float is stopping the flow to your tank there is still water running through your membrane and forcing it all down the drain. That shouldn't effect your DI though unless your unit is hooked up wrong. Are you going only by the color of the DI or by the TDS shown on your meter? Mine changes color quite a while before I measure any TDS on the output.
]]> Thu, 05 Dec 2013 13:40:43 +0000 http://www.utahreefs.com/forum/forum_posts.asp?TID=68157&PID=546082&title=di-resin#546082 <![CDATA[DI Resin : Do I see a theme here? SpectraPure...]]> http://www.utahreefs.com/forum/forum_posts.asp?TID=68157&PID=546081&title=di-resin#546081 Author: Fatman
Subject: 68157
Posted: December 05 2013 at 1:37pm

Do I see a theme here? SpectraPure filters?
]]> Thu, 05 Dec 2013 13:37:41 +0000 http://www.utahreefs.com/forum/forum_posts.asp?TID=68157&PID=546081&title=di-resin#546081 <![CDATA[DI Resin : 700 is above the EPA limit for...]]> http://www.utahreefs.com/forum/forum_posts.asp?TID=68157&PID=546073&title=di-resin#546073 Author: ReefdUp
Subject: 68157
Posted: December 05 2013 at 12:52pm

700 is above the EPA limit for city waterif I remember correctly. ]]> Thu, 05 Dec 2013 12:52:08 +0000 http://www.utahreefs.com/forum/forum_posts.asp?TID=68157&PID=546073&title=di-resin#546073