Jump to content

RODI Issues


Dukie

Recommended Posts

I've been having a lot of trouble with my RODI system. The RO unit seems to be good for about 1.5 weeks regardless of how much water I make. Every time I take it out to replace it, it has a hard white crust all over it. I'm guessing this is clogging the RO unit since my water production comes to a stand still and my TDS is usually around 90-130 ppm before the DI resin once I end up replacing the RO unit. If I had to guess, it would be because I'm in Franklin and we have VERY hard water.

Has anyone had a similar issue? And would having a water softener installed help this? How would a water softener effect the filtration and overall RODI water quality? I've tried both draining the RO container after use as well as leaving it pressurized, and neither seems to help. 

I'm using the BRS 5 stage 75 GPD system, and I have a booster pump in front of it.

Any help is appreciated.  

 

Link to comment
Share on other sites

Is it hooked up right?  There are guys in AZ that have water in the 600-900 TDS range and don't have issues except for burning out DI.   If everything is right, I would give Spectrapure a call, they specialize in this and it might save you money over a water softener.

 

What is your inbound water TDS?

Link to comment
Share on other sites

I too am on well water with a softener and I don't have any issues.  I have the BRS 6 stage water save without a booster pump and only 50psi.  I measure 2-3 TDS coming out of the membrane and zero out of the dual DI.  I can't until this weekend but I will measure the TDS of the water from the softener and pre-softener just to give you an idea if there is a difference, curious my self.

Link to comment
Share on other sites

I'll add to this. My water coming in is at 60-70TDS. Its at 9 on the hardness. I added a water softener. My TDS coming out of the softener is about 80-90 TDS. It coming out of the softener is in salt solution ( easier for the membrane)  Pre-filters and carbon wont pull out lime or calcium in the water. That's the membranes job. TDS coming out of the membrane should be about 98% lower than the TDS going into it. EX if TDS going in the membrane is 100, it should be 2 TDS coming out. Do a cal test on the water supply coming in.  Mine was high and causing it to plug and I found a used softener and plumed it to it.  Your membrane should last years if pre treatment is done. Here is a pic. 

IMG_0423.JPG

Link to comment
Share on other sites

Appreciate all the feedback. I will test my water before the membrane tonight. I don't remember what the scale of measurement for hardness is, but when I had someone come out to install my new water heater they measured it. I remember them saying >20 units was considered very hard water and I was reading closer to 50. 

 

The plumbing came pre assembled, and I double checked it. I have water from hook up --> to filter and then 2 carbon filters --> booster pump --> RO unit --> 2 DI canisters. It was originally a water saver 2 RO membrane system but I damaged one of the canisters for the RO membrane and now it just has one.

 

I'm flying through RO membranes and its costing a fortune. I get around 60 Gal of RODI water per membrane if I'm lucky before it slows down to probably 2-3 gallons per day. With my tank that's about 2 10% water changes and 3 weeks of evaporation. I flush the system often but after awhile the flush doesn't lower the TDS coming out of the RO.

Link to comment
Share on other sites

You might need a different flow restrictor on the waste water line out of the RO/DI since you are only doing half the GPD of the original.  I've run the same membrane for 6 years now and get about 99% rejection at my 75 PSI in.

 

What is your inbound PSI?

Link to comment
Share on other sites

The guy came to install my water softener this morning. These was an issue so he has to come back next week to finish up. I had him test the water and the hardness was 24 (I forgot, again, to ask for the units). 

My PSI after the RO membrane without the booster pump varies from around 45-55PSI. With the booster pump I'm at ~75PSI. 

I took a look at my flow restrictor for the waste water and I think I may have figured out my issue. The flow restrictor seems to be clogged. I'm getting 0 waste water from the system.... I'm guessing that is destroying my RO membrane pretty quickly. I just ordered a new one... we'll see how things go once I have that and the softer water.  

Link to comment
Share on other sites

I ordered a new flow restrictor, RO membrane, and all new tubing. Once the water softener is up and running I'm going to replace everything to start with a "clean" system. Hopefully that will do the trick.

Right now I'm leaving my flow restrictor slightly open so that I do get some waste removal. Its helping but i think the RO membrane I have in there now is in rough shape. My TDS out of the RO is sticking around 55 TDS. I can't find my hand held TDS meter so I haven't been able to test what the TDS into the system is. Hopefully the water softener and new flow restrictor correct my issues. 

I'll update with how the system is running next week once the softener is running. 

Link to comment
Share on other sites

Water softener went online Tuesday, and my new RO membrane and restrictor valve came today. I can for certain say the main issue was a clogged restrictor valve. The new one is making much more waste water than I ever remember seeing. My water before the water softener is 320ppm and then 344ppm after the softener. Water coming out of the RO membrane is 6-7ppm so that's about a 98% rejection rate. I usually was around 17ppm with a new RO membrane before.

The main issue here is I was trashing RO membranes because the waste the RO membrane was pulling out had no way to be removed. Just for the sake of torturing myself I looked on BRS to see how many RO membranes I've ordered in the past 12 months. It's 13.... what a waste. But I guess now I know better. Hopefully I won't need to buy a new one for a long long time. Not to mention the crazy rate I was going through DI resin since that was doing most of the work..... 

Lesson learned! (the hard way)

  • Like 1
Link to comment
Share on other sites

7 hours ago, MrsBugmaster said:

Glad it is turning around for you. Wow, that's a lot of membranes! They should last at least 3 years. 

+1 on that. As long as you change your pre filters, your membrane should last 3yrs or so. 

 

Even though you have high PPM's, it going through the softener changes it to a salt TDS. This makes it all very soft on your RO filters. 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...