DI, TDS, and Resin

[Alchameth]

After reading all the complaints about single digit TDS coming out of RO; figured my water has to be toxic at the TDS I come in at. Tested the water after I moved in, and it comes in at around 690-720... no joke. So I put in a nice softener system and supposedly a top of the line RO system. Now it actually comes in higher at 730-750. Welcome to AZ, what can I say. So the RO nets me water with a TDS average of 46-50, so 94%ish, but I know at 55PSI I am not getting the efficiency I could be nor the 1:1 ratio they boasted about on this system...

But, even with high TDS like that my tanks do well, but they could be better, right??? So I decided to pickup a dual canister DI setup (probably should have gone for the tri, but storage is limited). So given my TDS, my first batch of 15G used up about 25% of the first canister.

I did spend an hour installing a Smart Buddie RO booster (thanks to the fittings used on this premium system ) and that got my TDS down to around 25-27, but that still leaves me going through a lot of resin I'm guessing...

So we took the scenic route getting here, but where does one buy quality and/or inexpensive resin?

 

[piranhaman00]

After reading all the complaints about single digit TDS coming out of RO; figured my water has to be toxic at the TDS I come in at. Tested the water after I moved in, and it comes in at around 690-720... no joke. So I put in a nice softener system and supposedly a top of the line RO system. Now it actually comes in higher at 730-750. Welcome to AZ, what can I say. So the RO nets me water with a TDS average of 46-50, so 94%ish, but I know at 55PSI I am not getting the efficiency I could be nor the 1:1 ratio they boasted about on this system...

But, even with high TDS like that my tanks do well, but they could be better, right??? So I decided to pickup a dual canister DI setup (probably should have gone for the tri, but storage is limited). So given my TDS, my first batch of 15G used up about 25% of the first canister.

I did spend an hour installing a Smart Buddie RO booster (thanks to the fittings used on this premium system ) and that got my TDS down to around 25-27, but that still leaves me going through a lot of resin I'm guessing...

So we took the scenic route getting here, but where does one buy quality and/or inexpensive resin?

A water softener will not lower TDS but will exchange the minerals for salts that are easier on RO to remove, you made the right move there.

94% rejection is low. Looks like with booster you are now at approx 96%. Not bad, could be better. What membranes are you using?

I have 5 DI canisters as the final 5 stages. I buy bulk bags on amazon that fill the 5 canisters at one time so none is leftover. I have 7 TDS going into the DI and get about 150 gallons per canister. So yes you will burn through a lot of resin.

Im wondering if you could pump your RO water through the RO again, you would waste way more water but save more resin. Not sure what is better.

 

[KStatefan]

I would look at your membrane and waste water. With your incoming TDS i would not run it any less then 4:1. If you could get your rejection rate up to 98% that would cut your resin use in half.

 

[Alchameth]

A water softener will not lower TDS but will exchange the minerals for salts that are easier on RO to remove, you made the right move there.

What membranes are you using?

I buy bulk bags on amazon ...

I get the softener, knew that, just didn't expect higher TDS.

Ultima is what came with it and I just replaced the sediment, 2 carbons, and post carbon. The RO filter is only 2 yrs and I'd say I use about 3000-3500G a year. I've no problems replacing it sooner if there is a better option to go with.

Do you have a link to what you get on Amazon?

I would look at your membrane and waste water. With your incoming TDS i would not run it any less then 4:1. If you could get your rejection rate up to 98% that would cut your resin use in half.

Not sure I get what you are referring to with your waste water and 4:1 comment?

 

[piranhaman00]

I get the softener, knew that, just didn't expect higher TDS.

Ultima is what came with it and I just replaced the sediment, 2 carbons, and post carbon. The RO filter is only 2 yrs and I'd say I use about 3000-3500G a year. I've no problems replacing it sooner if there is a better option to go with.

Do you have a link to what you get on Amazon?



Not sure I get what you are referring to with your waste water and 4:1 comment?

I use this LINK.LINK

Replace your RO now, spectrapure is considered the best I think.

@KStatefan means increase your reject water to lower your TDS.

 

[KStatefan]

You mentioned it being a 1:1 system in your original post i would change the flow restrictor to get closer to 4:1 What is the membrane that is currently installed? Dow upgraded their Filmtec membranes a couple years ago and now get 99% rejection out of the upgraded 75 GPD membrane so if you have an older one you could gain efficiency by replacing it.

If you do not have a way to bypass the resin when you start making water I would also add on so the TDS creep would not make it to your resin.

 

[Alchameth]

Thanks for the replies you two!

I got the Aquatic Life booster so all that stuff (flow restrictor, checks, shutoffs, flush, etc) gets removed during the install and is handled by the unit. I can't find the specs on what they use internally for flow restriction, but know it starts with a membrane flush every time it's activated. Sure I could take it apart and look, but I just installed it so... nah.

My RO housing is sealed, so gonna pickup a DOW Filtec and membrane housing from BRS. Since my water is so hard and my pressure on the lower end, probably shouldn't wait 3 years even though I'm not running that much through it annually. I've already notice with the booster that it tastes better so there is that.

Think I will have to pull the drain and see what I am getting for wasteroduct ratio before making up my mind.

 

[ingchr1]

To confirm,

Well water?

What type of resins are you using? Separate anion and cation, mixed bed, both?

 

[Alchameth]

City water, mixed bed in both. Bought the BRS dual canister that came with mixed carts prepacked.

 

[ingchr1]

Ok, I'm on well, 500TDS and was going through mixed bed due to high CO2. I switched to cation, anion and mixed to get significantly more out the resin. Right now only the anion is getting used up. TDS into the resins is 10-20.

Not sure if this will help your situation or not, others may be able to chime in.

 

[Alchameth]

Well after installing the booster pump and letting the first 30s or so runoff before pushing it through the DI, my next batch seems to have used 5% at most with a TDS on the input registering around 11-14. Hope it gets even better with the new membrane when it gets here, but even if it stays in that 11-14 range, I can live with it.

Think I am going to tap a 3 way T in right after the RO and bypass the last coconut carbon filter so I don't burn it out needlessly, which will still allow for drinking water from the storage tank to be had while making tank water. Can't remember how many times I've gone out for water in the middle of the night because I forgot to get a glass before. Too bad I didn't think about that better when I first setup the line tap.

 

[KStatefan]

Carbon after your membrane for your RODI?

 

[Alchameth]

Carbon after your membrane for your RODI?

Yes, my RO system was purchased as a premium drinking water system, ya right... with what I know now and the mods and parts I removed to add the booster my extended warranty is probably void! LoL... So to sell that they have a final carbon after the membrane. Since says to replace every 2500Gal I wanted to move my tank water to before it, but I've been thinking abut scrapping and replacing with a mineral block to add stuff back to my drinking side, no consequence for the tank water discussion.

I originally tapped into the line after that carbon as it was the right size line and went to the faucet and allowed me to pull from the storage tank. With the booster it's making water faster than the DI can process is so the storage tank is still usable at the faucet while making tank water, but to simplify it and keep the drinking and tank processing separate I will be moving my DI to right after the membrane before said carbon filter which is what I should have done to begin with.