Di resin

[jeff williams]

was wondering if Di resins are all the same "excluding color changing vs non color changing" are there better quality ones that last longer ? He's my reason , new system Ro Di, tds going in 350 coming out of Ro membrane 40 ppm. Water psi is good 60. Di resins lasts about 100 gallons. Also water is hard.

 

[KJAG]

@AZDesertRat

 

[cmcoker]

Did you flush the sediment and carbon filters individually before connecting the membrane?
Are you sure the membrane is properly seated?
How are you testing TDS?
I'd be less concerned about the di resin and more concerned about the poor rejection rate of the membrane, 88% is not very efficient.
Spectrapure says the difference from 96% to 98% rejection doubles the lifespan of your Di resin.. Imagine what the drop to 88% is doing

Also, check the production to waste water ratio.

 

[jeff williams]

Flushed sediment and carbon filters first the installed membrane and flushed for about 20-30 min per instructions then hooked up Di and flushed and discarded first two gallons.
Ro membrane install is pretty straight forward can't see how I could screw it up. And tds is measured with a hand held tds meter did not buy the cheap one went middle level can't rember the mfgs name.
One thing I have noticed is 98% reduction rate comes with some catches like running it first through a water softener with an in tds of like 150 ppm water temp 70 deg and pressure 60 psi. So idea circumstances give a 98% reduction

 

[skim]

Do you know what membrane you have in the unit?

 

[cmcoker]

Flushed sediment and carbon filters first the installed membrane and flushed for about 20-30 min per instructions then hooked up Di and flushed and discarded first two gallons.
Ro membrane install is pretty straight forward can't see how I could screw it up. And tds is measured with a hand held tds meter did not buy the cheap one went middle level can't rember the mfgs name.
One thing I have noticed is 98% reduction rate comes with some catches like running it first through a water softener with an in tds of like 150 ppm water temp 70 deg and pressure 60 psi. So idea circumstances give a 98% reduction

It's possible not to get the membrane in all the way or a little crooked, allowing water to bypass, not saying that's necessarily the case.

I understand the ideal conditions but I still feel like 88% is pretty low and something isn't right.. If it was me I would contact the company you got it from and ask for help troubleshooting.

+1 what membrane? What rodi unit?

 

[jeff williams]

Do you know what membrane you have in the unit?

Dow 100 gpd marine depot unit

 

[cmcoker]

Dow 100 gpd marine depot unit

Ok, I would definitely double check the membrane is seated correctly, then call them and talk to them about the tds.

Just for an example, I have a bulkreefsupply unit, dow 75gpd membrane. 50-60psi (apartment, it's lower on the weekend when more people in my building are home)
My tap is around 280 tds and I'm getting 6 tds on my post membrane so like 97% rejection. Im using a spectrapure di resin to take it down to 0.

At 40 tds you are going to spend a fortune on di resin, no matter which one you are using. Got to figure out how to reduce that post ro TDS.

 

[jeff williams]

Ok, I would definitely double check the membrane is seated correctly, then call them and talk to them about the tds.

Just for an example, I have a bulkreefsupply unit, dow 75gpd membrane. 50-60psi (apartment, it's lower on the weekend when more people in my building are home)
My tap is around 280 tds and I'm getting 6 tds on my post membrane so like 97% rejection. Im using a spectrapure di resin to take it down to 0.

At 40 tds you are going to spend a fortune on di resin, no matter which one you are using. Got to figure out how to reduce that post ro TDS.

Thanks for info I'm double checking the membrane and giving MD a call

 

[Brew12]

Thanks for info I'm double checking the membrane and giving MD a call

Have you tested your water for Chloramine? The Chloramine itself will be absorbed by the activated carbon but some of the byproducts will (like ammonia) will burn out a DI resin filter fairly quickly. I have also heard that chloramine can damage an RO membrane.

 

[jeff williams]

Have you tested your water for Chloramine? The Chloramine itself will be absorbed by the activated carbon but some of the byproducts will (like ammonia) will burn out a DI resin filter fairly quickly. I have also heard that chloramine can damage an RO membrane.

Ya I do know chloramines and chlorine will damage an Ro membrane. I tested my water and total and free chlorine were extremely low, the test strip color change is almost non existent. Also backed up that test with talking to my local culligan guy he said both are very low in our supply.
Also double checked membrane install it's good and called MD they said its something in the water but that don't make sense because my local reefers are not having this problem granted everyone's system is different

 

[jeff williams]

If you TDS is 40 after the membrane, the di lasts 100 gallons is kind of hi double check your TDS meter..

..My handheld TDS meter was giving me 0 TDS for a long time...One day I got the BRS gauge and it showed me 2....awwww

Ya hand held meter is new and tested it on distilled water and Di water

 

[sithrico]

Is your flow restrictor set right? We had this exact conversation 2 weeks ago locally with someone and found the restrictor wasn't set correctly. Check this out.

 

[cmcoker]

Ya I do know chloramines and chlorine will damage an Ro membrane. I tested my water and total and free chlorine were extremely low, the test strip color change is almost non existent. Also backed up that test with talking to my local culligan guy he said both are very low in our supply.
Also double checked membrane install it's good and called MD they said its something in the water but that don't make sense because my local reefers are not having this problem granted everyone's system is different

Even if it's something in the water, you need a solution...

Maybe some #reefsquad members could help you troubleshoot better...

 

[jeff williams]

Is your flow restrictor set right? We had this exact conversation 2 weeks ago locally with someone and found the restrictor wasn't set correctly. Check this out.

That's some good info thanks. My rejection valve isn't adjustable however I did notice when I purchased a back flush kit the rejection chock in it was noticeably smaller than what cane with the unit and I do have hard water so I think I'm going to change my feed line from the out put side of my water softener and see if this helps thanks

 

[jeff williams]

Even if it's something in the water, you need a solution...

Maybe some #reefsquad members could help you troubleshoot better...

Just a thought I have hard water in my area my Rodi unit is plumbed in before my water softener do you think moving it to the output side of my water softener it would make a difference?

 

[cmcoker]

Just a thought I have hard water in my area my Rodi unit is plumbed in before my water softener do you think moving it to the output side of my water softener it would make a difference?

Yes, I would definitely do that. The way I understand is that the softener exchanges sodium for calcium and magnesium. The membrane will have an easier time removing sodium, so it will help the membrane last longer.

I don't know that it will do anything to help your tds out of the rodi unit though. Maybe someone smarter than me can answer that..

 

[sithrico]

Just a thought I have hard water in my area my Rodi unit is plumbed in before my water softener do you think moving it to the output side of my water softener it would make a difference?

Yes it totally will. Mine is plumbed after because Az is really known for hard water. It was suggested when I first purchased to put after the softener. You'll probably get better flow as well.

 

[cmcoker]

I saw @Frop posting in the BRS dual membrane thread, he had insane tds out the tap, uses a water softener, and I think getting it down to 10 tds?

Maybe he could have a suggestion for you..

 

[jeff williams]

I saw @Frop posting in the BRS dual membrane thread, he had insane tds out the tap, uses a water softener, and I think getting it down to 10 tds?

Maybe he could have a suggestion for you..

I'll hit him up