RODI After Softener

[wachee]

Here is a post I posted to my local forum. I lost almost 10,000 dollars of corals this year to a very slow death. I tried everything I could think off, but whatever it was, kick my butt. I was almost out, when my wife convinced me to try one more time. I am in sixth week of a new start up, and i am worried that I am seeing some of the same things happening again.

Many of you know about the problems I have had this year. I have a new theory. At some point last year, I needed a lot of RODI water so I went to Collagen to get 60 gallons or so. While there discussing my situation, he tried to get me into one of their systems for my water needs. I explained that I would consider it, but for now my 75 gpd should be fine. He then explained that I should take water after the water softener, which would be easier on my membrane. I asked him if he thought the possible salt would matter, he thought that there would be a minimum amount and that the positives would out way the negatives. I was just talking to my wife about the tank and this came to my mind. i will be moving where I get the water from to before the softener and dumping 500 gallons of stored RODI today. I wonder if this is the problem. My tank is doing fine, but I feel that something is still off, I will be ****** and grateful at the same time if this was the problem the whole time.


What do you guys think? I realize that your opinions will most likely be just opinions, but I hope someone might know something about this situation.

 

[Reefer93105]

I get my RO/DI after my water softener and have no problems. I use regular softener salt. Check your softener salt if there are any additives. Also there are alternative potassium pellets out there. That might have some effect if you are using it. Just my opinion.

 

[Aqua fire/medic]

Interesting subject...... Following

 

[Velodog2]

I am interested to hear more learned responses than mine possibly is. I take water from before the softener for the RODI and always have. I have extremely hard water.

How well do you purify your water? Down to zero TDS? If you take everything out then it wouldn't seem to matter what was in it to begin with.

 

[goodtimes]

After the softener is typical, I wouldn't think that would be it.

 

[Buckeye Field Supply]

After the softener is typical, I wouldn't think that would be it.

Right on.

 

[AZDesertRat]

RO membranes love softened water, it does much of the work for it, kind of like pretreatment. Membranes are designed to removes salts, look at all the membrane desalination plants in the world.

 

[goodtimes]

Good luck with your search for the root problem.

 

[Velodog2]

Ok this is interesting. So what is the downside of not using the softened water for the RODI? I get about 6 ppm of TDS going into my DI resin bed. Should I change?

 

[goodtimes]

The softener makes the membranes job easier. Like someone side earlier the softener acts as s prefilter. The downside to it is shortened membrane use.

 

[Velodog2]

I'm all about making anyone's job easier, but will the membrane do it better than 6 ppm TDS if I include a water softener before it?

 

[wachee]

You should be getting 0 TDS after your DI resin. My concern is not TDS or Ions, I was thinking that maybe the softener salt my be letting something through. Didn't know that so many do it this way. So that can't or shouldn't be it. Thanks for all your responses. I was kind of hoping that some chemist was going to come on here and say duh. The I could feel good that I solved the problem that I had this last year. Again, thanks for all your impute.

 

[kracer1025]

I had problems years ago when running my rodi after the softner. A chemist friend of mine broke down in scientific terms (that there is no way I could reproduce for you) on how a softner is not ideal for making my aquarium water. I had similar problems of multiple coral deaths with no known rhyme or reason. All my parameters were spot on test after test and still things were dieing. I did several large water changes with pre softner water and since continued using pre softner water and my problems have stopped. I know the softner helps to extend the life of your membrane and sure just like everything else in this hobby there are people everywhere using softened water without a problem but every tank is different and I say if it saves your tank in the long run it's worth a try.

 

[ReefFrenzy]

I have a well and have my RODI unit installed after the "whole house" water softener/filter. We go through about three fifty pound blocks of salt in the softener every 6-8 weeks. I make a ton of water for our six SW systems and have made countless gallons for others when I did service work and helped friends get tanks going.

I did not see any loss of livestock or other unusual problems related to the water. I use Reef Crystals salt, for now.

I'm not a chemist but I would hope that zero TDS is all that matters coming out of the RO/DI.

Good luck, and I must admit I never have seen this topic on any of the forums we sponsor so I am following along.

 

[Velodog2]

You should be getting 0 TDS after your DI resin. My concern is not TDS or Ions, I was thinking that maybe the softener salt my be letting something through.

That's 6 ppm after the RO. The DI takes it to zero. Sorry for semi-hijacking your thread. My point would be that TDS is a measure of ions, and they are the "somethings" that you would worry about. Get rid of them and you just have water. Unless you were worried about isotopes.

 

[wachee]

Velodog2, my point is that I don't know what I am worried about. This just came to mind. I was all but out of this hobby, because of the hours of stress and work put into solving this problem. I even started showing my system to be sold. I just don't know. What I have found with the membrane is that my output fluctuates some, but after running over a hundred gallons consistent, my TDS begins to drop to 2 and sometimes 1. I think it may be due to the membrane getting plugged. After I flush it, it goes back up to 4 and sometimes 6.

 

[Velodog2]

I get it Wachee and I feel your pain. Also I was a little confused by your last post as I would expect flushing your membrane to lower TDS not raise them.

Anyway, to cut to the chase there are two takeaways. It is pretty unlikely that your water softener is your problem. If you are still concerned and want peace of mind there doesn't seem to be any downside to replumbing it to use unsoftened water. But don't get your hopes up too high that this will fix your problem, although Kracer may disagree.

Edit. After further thought and rereading the original post. If you are losing $10,000 a year in coral then by all means replumb. If there is any question about your membrane or rodi unit in general, replace it.