The Cost of RODI water

[Airtex]

We use a lot of RODI water ( approx 50 gal week ) and I was wondering what it actually cost to " make water ". We live in western palm beach county and have well water (634 TDS) so the actual cost of the water is some electric and a bag of salt...but by the time it comes out as RODI it has been through many filters which obviously cost big money.

I recently switched to a 99% Spectrapure membrane with auto flush and the entering TDS at DI resin is 9 which is fantastic compared to the old AWI that i had. However we use up those expensive cartridges very quickly so I decided that we would just use refillable DI cartridges and skip their special MAXpur / silicabuster cartridges etc.

After about 3 months of collecting data it appears that we are paying .86 cents a gallon. (not including pump electric or salt)

 

[wild1]

I'm paying $.50 a gallon at the LFS

 

[Miamiangler]

But you never know how good the RO water is at the LFS. better to make your own .LFS probably don't use a 6 stage RODI system

 

[mrx66699]

You can make things more efficient and closer in waste/ro by adding a second RO membrane and reprocessing the waste another time .....added cost will be a second RO housing and membrane and possibly a booster pump if you do not already have the water pressure to do it......very simple and cheep to do and it will save you substantially on your waste......normally its a 4 to 1 waste ratio and you can get it substantially closer to a 1 to 1 with this simple setup.........

by the way your automatic flush is worth the weight in gold for sure when you are working with reducing waste and lengthening your life of your ro membrane and your di.....used to flush it manually but now its automatically done and is so much more efficient

 

[Airtex]

Yes some of the LFS in the WPB area are known for 2-3 tds one even worse. The other issues is convenience ...10 buckets to the store and back every week is a pain in the butt.

We have a 55 gal storage tank and on demand pump piped into a utility sink....best thing I built in the tank room. The on demand pump also feeds the ATO based on float switch...which also automatically waters the mangroves.

That is a great idea to reprocess the waste! It was amazing what just changing to the 99% spectrapure membrane did to the TDS. I do have a booster pump and currently run about 80 psi....and yes...CANT live without the auto flush....worth every dollar.

 

[mrx66699]

Are you saying you have your rodi on a float switch and water running all the time ? If so how is that working with the auto flush as it would be flushing every hour and wasting a lot ....or does your water only come on when the 55 is low as it should?

 

[Airtex]

The RODI system simply runs as required to keep a 55 gal tank filled based on a float level in the tank.

The Spectrapure membrane flushes as required...I don't control it...I would guess based on pressure drop it cycles to flush and commands the pump on to backwash it.

The storage tank is piped to an on demand pump that goes to the faucet at the utility sink and also goes to the sump for top off water based on float level in the sump. When the sump gets top off water the sprinkler turns on for the mangroves.

 

[mrx66699]

You should have that float switch in your ato storage container in a dual stage with two of them.....one to turn it on after a few gallons is used and then one to turn it off when it is full.....your system will produce more efficiently this way ....produce a few gallons at a time instead of constant on and off keeping the storage container full....di will last longer and so will your ro membrane as its made to produce gallons not dropps

 

[Airtex]

That is a good point !!...never really thought about it turning on just to satisfy level throughout the day to make top off...I really only focused on the day I do water changes for 3 tanks.

Thanks for the tip....Anything we can do to reduce the cost of our addiction makes our loved ones happy !!


Keith

 

[Wings6010]

The Cost of RODI water

I recently got into a argument with the owner of two lfs in the palm beach area because at both shops he was selling "0 TDS" RO DI when I checked the TDS at the stores in a clean cup and it was 168 at one shop and 280 at the other I was appalled! They obviously don't change out the DI and when I brought this to there attention they told me they hired a new rodi service company to take care of the issue. That all great but for the past at least month or two they have been charging all these customers including myself $.60 for RODI or $.75 for premixed salt which was as dirty as the water coming out of my sink! And of course no refund or apology and they're still selling the same crap to unknowing customers! Since the. I bought a 75gpd brs value plus system and never looked back, but I'll tell you one thing I spend A LOT "hint hint" of $$ on livestock sps fish etc and they'll never get another cent from me..

For peace of mind I recommend not getting rodi from your lfs however much it cost.

 

[Airtex]

Wings you are not alone. Those stores have a reputation. No excuse for not having zero water. In a month they will sell those same people that bought water something to control algae !

Unfortunately a lot of the LFS in palm bch have a big turnover in employees which causes lack of maintenance and a tremendous amount of misinformation given to people just getting into this hobby.

I am amazed at what I hear being told to people. It is just about making money for most stores... however there are a few guys that are in the business to make money but they also love and are addicted just like we are....and yes their water costs more.

Keith