DI system only system questions

[Freenow54]

You were not trashed for suggesting di only, which you did not do. I criticized the suggestion to send waste water back into the potable water system using a booster pump diy.

DI only can be fine, but expensive

You were not trashed for suggesting di only, which you did not do. I criticized the suggestion to send waste water back into the potable water system using a booster pump diy.

DI only can be fine, but expensive.

I should have been more explicit. You and one other did not insult me but one did. They probably enjoy it and I am again probably not the only one. The response from them was a HA HA Ha not a typed reply.
Anyway I know I did not say anything regarding DI only. As far as sending waste water back int the system, I pulled out my manual, and provide what I think should make clear as to why I said that it was impossible assuming of course which would include any RO system that it was functioning and installed and used properly. I hope this diagram will alleviate your concerns. I had to satisfy my concerns as well your comment on this is important because I respect your wealth of information and need my reputation intact

as well

 

[Freenow54]

Sodium hydroxide generally

So do you put it into a separate container in your system? Also do you just soak it or what is the procedure

Thanks

 

[Freenow54]

What is your opinion of this Randy?

 

[Dburr1014]

How do you recharge the anion? Also it sounds like you buy it and house it separate from one to the other is that correct?

Soak in sodium hydroxide for a few minutes until it changes back to color. Rinse in a couple gallons of ro/di water and run until tds is close to zero again. IME, a quart or so.

Yes, seperate. I run cation first, then anion, then mixed bed. All after my ro filter.

 

[Freenow54]

Yes, I meant canister. It seems like my water does not consume cation nearly as fast as the anion; fortunately, recharging the anion seems like a fairly simple process.

So as to the Cation is it rechargeable?

 

[Dburr1014]

So as to the Cation is it rechargeable?

Yes, that also can be recharged with muriatic acid. Same procedure as I outlined with anion.

You can also do mixed beds with these chemicals. They will seperate them doing so and then you will have to mix back together.

 

[ScottD]

Yes, that also can be recharged with muriatic acid. Same procedure as I outlined with anion.

You can also do mixed beds with these chemicals. They will seperate them doing so and then you will have to mix back together.

It never occurred to me that you could get them separate and mix them yourself. I go through it fairly quick I presume because of some CO in my water so I could maybe mix it myself with a different ratio so I’m not wasting cation.

 

[Garf]

It never occurred to me that you could get them separate

You can buy them mixed if you want. When you add the sodium hydroxide, the anion floats, which allows separation so that the cation can be charged separately.

 

[ScottD]

You can buy them mixed if you want. When you add the sodium hydroxide, the anion floats, which allows separation so that the cation can be charged separately.

Yes I have been buying them mixed which I assume is a 1:1 ratio. I was thinking what if I bought them separate and mixed them myself at like a 3:1 ratio of anion to cation since I burn through the anion quicker. Ultimately I’ll probably get more canisters and run a separate one for each.

 

[Shirak]

It never occurred to me that you could get them separate and mix them yourself. I go through it fairly quick I presume because of some CO in my water so I could maybe mix it myself with a different ratio so I’m not wasting cation.

You could mix them yourself if you wanted to change the proportion yes. No clue what proportion they put into the mixed bed already but you are probably not using it up. You could also get color changing on both resins so you can see for yourself.

 

[Shirak]

Yes I have been buying them mixed which I assume is a 1:1 ratio. I was thinking what if I bought them separate and mixed them myself at like a 3:1 ratio of anion to cation since I burn through the anion quicker. Ultimately I’ll probably get more canisters and run a separate one for each.

If you want to use them fully then yes running them separate is needed, but you also need to run two in series so you can run the first one in line until it is fully changed color and the second is catching what gets past the first one before it's totally exhausted.

 

[Shirak]

You could do a single cation, two anion in series and a final mixed bed
You would be able to get the first cation used up pretty much entirely and since it needs changing so infrequently it's not the end of the world if it doesn't quite get all the way there.

 

[Freenow54]

Yes, that also can be recharged with muriatic acid. Same procedure as I outlined with anion.

You can also do mixed beds with these chemicals. They will seperate them doing so and then you will have to mix back together.

That would be an impossibility with the resin I showed you. It is to fine. Appreciate the education

Thanks

 

[Randy Holmes-Farley]

How do you recharge the anion? Also it sounds like you buy it and house it separate from one to the other is that correct?

Yes, they must be separate.

Recharging DI Resins

When DI resins are present as mixed bed filters, they are essentially one-time use devices that must be thrown away when depleted. These are the types supplied with many commercial RO/DI systems, and are what I use. Separate bed DI resins have certain advantages, however. In particular, if they are kept in different cartridges, they can be recharged. Trendy deals of the Makro Specials and exclusive price range.

The recharging process is essentially the reverse of the deionizing process (Figures 6-8). A strong acid (usually hydrochloric acid, HCl) is used to swap H+ for all of the positively charged ions on the cation-binding resin (Na+, K+, Ca++, Mg++, etc.). Likewise, a strong base (usually sodium hydroxide, NaOH) is used to swap OH- for all of the negatively charged ions on the anion binding resin. Both hydrochloric acid and sodium hydroxide are readily available and inexpensive. They are, however, potentially dangerous to work with. The detailed procedures and safety precautions are beyond the scope of this article, but can be found elsewhere online.

Reefs.org: Where Reefkeeping Begins on the Internet - Tap Water Purifier Recharging Article - Instructions

By Gary Deutschmann

web.archive.org

 

[Garf]

Yes I have been buying them mixed which I assume is a 1:1 ratio. I was thinking what if I bought them separate and mixed them myself at like a 3:1 ratio of anion to cation since I burn through the anion quicker. Ultimately I’ll probably get more canisters and run a separate one for each.

I use 60:40 ish (Anion to cation). When recharged I don't fully mix them, I just layer them in the canister.

That would be an impossibility with the resin I showed you. It is to fine. Appreciate the education

Thanks

You regenerate in jugs if they are mixed bed. If you have separate canisters they can be regenerated in situ with a bit of ingenuity. What do you mean "it is too fine"?

 

[Randy Holmes-Farley]

What is your opinion of this Randy?

Arsenic should be very low in drinking water in the US before any treatment. The allowed EPA limit is 10 ppb.

Arsenic is a problem with well water in some parts of the world, and binding arsenic is actually why GFO was first invented for water treatment.

Both RO and DI should remove any residual arsenic in drinkable water.

Natural seawater has about 1.8 ug/L (1.8 ppb) arsenic.

 

[Randy Holmes-Farley]

If you have separate resins and recharge, what benefit is there to ever mixing them and then making recharge impossible until you separate them again?

 

[Freenow54]

I use 60:40 ish (Anion to cation). When recharged I don't fully mix them, I just layer them in the canister.

You regenerate in jugs if they are mixed bed. If you have separate canisters they can be regenerated in situ with a bit of ingenuity. What do you mean "it is too fine"?

The granular particles are to fine to separate

 

[Garf]

The granular particles are to fine to separate

When you add sodium hydroxide the anion floats, and you tip it out into another jug. The cation stays in the first jug, as it doesn't float, thus;

 

[KStatefan]

That would be an impossibility with the resin I showed you. It is to fine. Appreciate the education

Thanks

Old article with good instructions.

https://reefkeeping.com/issues/2008-09/nftt/index.php