55 gal drum for ro/di

If you store water in a 55g drum trash can or whatever you choose. it is best to have it in a dark location with a small powerhead or pump, something to keep the water from getting stagnant. You should be able to store water for quite a while like that.
I acquired a 55g drum from work, bleached and rinsed several times and have not had any issues.

 

heck AZ...usually beats me to most RODI threads.

If by $900 you are referring to the UHE unit, then I dont think you will find a comparable unit anywhere else. Well, I guess i have not looked that hard, but you get my point. Most units are from 3-4(+):1, waste/RODI.

And spectrapure makes some of the best units on the market. AZ gives a much better rundown. but, suffice to say,that they have the best membranes/resins in the RODI field, they test their membranes in house, and have done extensive testing/research. I am super happy with my maxcap unit, but am switching to the UHE sometime in the near future to reduce on water usage.

 

as for the storage. any container will hold water. But, I would look for a food grade container or a drum that previously held food grade materials.

I didnt realize the water had to be "stirred". i think if the container is sealed, and relatively dark you should be fine. but, that may require a "google" just to be sure.

 

It doesn't HAVE to be stirred. If you think about it, it technically isn't completely sealed and some air gets in. Adding something to keep the water moving will just help from any particles from building up and algae growing. It basically buys you time till you can use and replenish the water without any issues. IMPO and the info was also given to me by a colleague who runs our DI water tank filtering systems for the navy.

 

We bought some Emergency Essentials "earthquake" barrels for our water storage...a 55 gal for RO/DI and a 35 gal for SW.

They're for drinking water, so they come ready to go, and can be had from here: WATER STORAGE

Here's a pic of our barrels:

l h

Altho it's not shown in the photo (we had just gotten the barrels), we fitted each barrel with an internal feed pump, and the SW barrel has a mixing pump in it as well.

 

I own the UHE system myself and I can tell you there is no system on the market even close. Others attempt low waste but the thing they are missing is the flush using stored DI water, none has it. This is why it works so well and why it is unique.

If your tap water TDS is low to normal, say 250 or less and especially if you are using softened water you can do well with their new autoflush systems with the 2:1 or 3:1 waste ratio. I would not attempt it if your water is hard or you have high TDS though or you will be in the same boat the other vendors are with frequent membrane failures and replacements. Membranes must be flushed, there is no way around it and its why they work. If you cut the waste you shorten the membrane life due to TDS solids building up on its surface and solidifying when it sits idle. When you flush with tap water at 4:1 you create the volume and the velocity to carry them away. When you cut the waste you lose that flushing so soft water and low TDS help. Stored DI works even better since it attracts or pulls the TDS out of the membrane and then they do a final flush and pickle or store the membrane in DI when idle so you have no TDS creep to worry about. Very unique and yes it is expensive but to me worth every dime.

My tap TDS is over 600, my UHE is over 5 years oldwith the original membrane and my RO only rejection rate is still over 99.4% to this day. I do use a water softener and I keep up with my regular maintenance but have found since there is much less water going through the system , filters last up to 18 months or more based on tests with pressure gauges and a low range chlorine test kit and DI lasts over 1000 gallons per cartridge using a COM-100 handheld TDS meter. Amazing system!

I store my ATO water in a covered 23 gallon Rubbermaid and water change water in five capped 5G drinking water jugs or a 32 gallon Rubbermaid on wheels. No stirring or air pumps are needed.

 

AZ: how exactly does one flush the membrane? and how often should it be done?

 

The purpose of the waste ratio is to continously flush the membrane while it is in operation. Most of the so called flush kits have no proven documented value and do nothing more than give you a warm fuzzy feeling like you have done something good, but all it did was lighten your wallet.

The flush kits bypass the flow restrictor but still use 1/4" tubing and additional fittings. Keep in mind they are on the waste side of the RO membrane, not the treated water side so don't flush anything from the treated side such as TDS creep. When you open the valve it slightly increases the waste flow, supposedly to scour the membrane. The fact is its not enough volume or velocity do do anything though, and the TDS that is there is only 20-25% higher than the tap water anyway. Keep the waste ratio where it should be according to your water conditions and no flushing other than the waste ratio is necessary.

If you want to flush something and actually get some bang for your buck, install a DI bypass valve between the RO membrane and the DI resin, on the treated water line. This allows you to manually flush the TDS creep which happens with all membranes to waste so it does not exhaust your DI resin prematurely. There are automated versions of this available too if you make water automatically but not cheap. By flushing TDS creep out you lenghten your membrane and DI life and realize a cost savings and better water quality.

 

holy crap i think im more lost than ever now lol