RO DI Unit

[seminolecpa]

Does anyone have any suggestions for a good RO DI unit. I bought mine on Ebay and it seems to be a huge water waster. I only need to make about 5-10 G per week. The water it makes tests out well but is seems to take me almost a day to make 15G.

 

[sfsuphysics]

How about you research a DI only unit? (with prefilters of course). Get the resin in two parts, then you can recharge it after you deplete it's capabilities, zero waste water.

As to the 15gpd, do you have a 25gpd unit? is your water pressure low?

 

[racrumrine]

I have had a Typhon III for over a year. TDS still 000.

http://www.airwaterice.com/product/1TYPHOONIII

Their customer service is great.

Best of luck,

Roy

 

[Elite]

How about you research a DI only unit? (with prefilters of course). Get the resin in two parts, then you can recharge it after you deplete it's capabilities, zero waste water.

As to the 15gpd, do you have a 25gpd unit? is your water pressure low?

No need for other filter.. just the DI unit?? Will that work??

 

[Mr. Ugly]

Deionizing resin works fine on its own. I'm using a modded Aquarium Pharmaceuticals Tap Water Purifier mixed resin setup.

I've separated the resin types, and recharge with NaOH and HCl. Cheap, fast, easy, and doesn't waste water. You can buy the AP TAP and cartridges online cheap when Fosters & Smith has a sale. Probably even cheaper to buy resins from Buckeye Field Supply. If you're into DIY, you could build a DI setup easily.

 

[sfsuphysics]

Well I'd still have the prefilters, sediment & carbon, but for everything else yeah no need for the RO membrane. resindepot.com is another place for resins, Cat. & An. (I can't recall how to spell the whole names )

I'm going to go this route when I get my downstairs set up, because it's my firm belief that while yes the RO unit has provided me with much great clean water it is also the source of a good amount of my aquarium problems because it takes so f'ing much time to make the damn water! I really don't want to wait around a day or two to fill up a rubbermaid (and this is with a 75gpd membrane!) not to mention it really makes needing to do emergency water changes an near impossibility. Infact on my 135 upstairs (which has been reduced to a few softies and a handful of small fish) I do water changes with straight tapwater and amquel plus (I believe Jim, bookfish, did this and this was on a SPS tank that had good stuff in it!). And I could go on about how I'm not satisified with a RO unit, the least of which is hearing the damn thing flushing itself on a cold night even though I'm not making water, i'd rather not pay the water company for water I really don't even waste!

Plus the great thing about DIY if you already have a RO unit, you have all the parts you need! I've kept my old DI resin containers so no need to buy them. I have the carbon/sediment prefilters, so no need to change them. Now just need to get a decent supply of the rechargers as Norman mentioned without getting red-flagged by the dept of homeland security.

 

[Mr. Ugly]

Hehehe... just get swimming pool acid and Red Devil lye from Home Depot

Yeah, use the carbon and prefilter etc. If you didn't have one, you could always get a cheapie HD under sink water filter.

My setup makes a gallon of DI in about 8-10 minutes.

I'm doing tap water and chloramine remover as well, for my prop tank. If Jim, and now Mike, says it's good...

 

[Raddogz]

Norm,

So you use Muriatic Acid and Red Devil Lye from HD?

How often do you recharge the resins?

 

[Elite]

So just tap water going through the DI unit??? What about stuff in the tap water such as copper .... ??

 

[Mr. Ugly]

Raddogz - Yup, the stuff you can get at HD or ACE hardware. The original AP TWP cartridges are good for about 50 gallons or so only. So I saved several spent cartridges and separated and recharged the resins.

Now, I'm running the cationic and anionic exchange resins from 3 cartridges in 2 separate columns. I think I've run close to 100 gallons through them and the color change indicator is barely starting to turn blue. So I figure it'll be a long while before the next recharge. Sorry I don't have anything more specific than that.

Elite - Organics in the water are trapped by carbon. Particulates are trapped by a 5 micron filter. Other "stuff" in the tap water would be in the form of positive or negative ions which would be adsorbed onto their respective exchange resins.

Copper ions are +2 and +3 cations. Phosphate is -3 anion, Iron is +2 and +3, Nitrate is -2.

Chloramine, I believe, undergoes catalytic decomposition on contact with the carbon. The decomposition products are trapped by the resin. That's also why you can smell ammonia if your resin is completely exhausted. The trapped ammonia gets released.

Use the color change resin or test with a TDS meter, and recharge the resin before it's completely exhausted. Or else, swap a fresh cartridge in line after the used one. Then you can leave the first one in place until it's completely spent.

 

[magma01]

how the heck do you separate the resins? is it just a lot of patience? Mr. Ugly, if you don't mind, can you snap a couple of pics of your setup and post it here?

thanks

 

[Mr. Ugly]

Hahaha.... lots of patience and a pair of tweezers

Seriously though, the 2 resins have different densities, and you can get them to separate when you add the NaOH recharging solution.

Here are some articles about the process:

http://www.reefs.org/library/article/twp_recharge.html
http://www.reefs.org/library/article/g_deutschmann_instruct.html

There is some other information floating around out there, but I don't have the urls handy. You could probably Google it though.

hth.

 

[sfsuphysics]

http://www.resindepot.com/shopdisplaycategories.asp?id=4&cat=Ion+Exchange+Resin

two at the bottom

 

[Vincerama2]

Wow, interesting! My RO/DI drives me nuts too. I can hear the wasted water and it really bugs me! For one thing, I'm paying for water that is being dumped for no reason, secondly, the water has gone through (in my case) 5 pre-filters ... and then dumped? That's good filtered water! Sure the concentration of whatever RO membranes reject is higher, but so what? That's stuff you would have drank without the filters anyway!

V

 

[Raddogz]

one very large wash load cycle cept' i like to wash with warm water as the wash cycle and rinse with the cold water.

 

[Vincerama2]

Alas, I have a front loading washer, so I can't load it with the waste water. Which is completely ironic, since Cal Water gave me a $75 rebate (or was t $50?) for buying a "water conserving" washer...meanwhile I'm dumping 100 times more water down the drain!

I think I'll plumb the "waste"into a container in the backyard for watering plants.

V

 

[sfsuphysics]

yeah hearing that constant wasting of water when there wasn't even any water being produced is what prompted me to go to DI only.

 

[Raddogz]

It makes your lawn (if you have one) nice and pretty.

 

[GreshamH]

I plumbed my friends RODI into his pond. It gets a continual water change, and that overflows into his garden

 

[Elite]

It's OK to use waste RO water for pond /w KOI??