ro water saving idea

[little_squid]

ok ill try to make this as clear as i can heres my thought i dont recall ever seeing this talked about so here it goes!

get a float valve and attach it to the top of a 5 gallon bucket and attach your tap water line to it.
add a ro pump at the bottom of the 5 gallon bucket to feed the ro unit.
have the waste line of the ro unit drain back into the 5 gallon bucket
so lets say every 5 gallons of water thats pumped thru the ro unit you will get 1 gallon of ro water and then the float valve will refill the 5 gallon bucket with 1 gallon of fresh tap water.

now i could see the water over time in the 5 gallon bucket getting full of impurities but if you emptied the 5 gallon bucket and started with new fresh tap water on a weekly or bi-weekly i dont see any harm.but would save alot of water!

any ideas or thoughts on this set up would be great

 

[exmt]

Hmm, I'm not sure if this would be bad for the RO unit, but wouldn't buying a booster pump defeat the cost of saving a couple gallons of water?

 

[little_squid]

in romeoville no water here is 3x the cost of most cities
also alot of people in florida could use a closed loop ro unit! i have seen signs at home depot sayin ro units waste to much water please buy bottled water

 

[scrager]

i too would like some info on this...anyone with personal experiences/experiments?

 

[RandyStacyE]

I've seen threads on this subject before. The waist would build up and be bad for the membrane if set up this way long term even if the water is changed daily.

RO units do an excellent job at filtering water because of the quantity of water that it waists. When impurities are caught by the membrane the waste flushes it out of the system ââ"šÂ¬Ã…"œfor goodââ"šÂ¬Ã‚.

The longer the unit runs, the less efficient it will become and greater the likelihood of damage to the membrane. In a way it would be like trying to recycle the exhaust from your car by routing to the air box. It will screw up the engine.

 

[tgunn]

You should consider using a rechargable cation/anion DI system. Do a search for Kati Ani and you'll turn up some hits on the system. The basic idea is you just skip the RO and do only DI (except the DI is rechargable if you use separate resin canisters instead of the typical mixed bed). Zero waste.

Anthony Calfo is a big proponent of this style of water purification..

Might be worth looking into if zero waste if your goal.

 

[little_squid]

well im going to try this out and will keep testing the membrane ect.. just wanted some thoughts on the matter i understand were randy is coming from but not all of the waste water imo is true waste! i guess even if you do this and it cuts the life of the membrane in half might still be cheaper than paying $150 a month in water bills new membrane is $80 and if you changed every 6 months you could still save a ton of money

 

[Reefski's]

collect the waste water and water your plants. then it is not wasted.

how much is your water? here in Los Angeles our water is about $3.00 per 1,000 gallons. or 0.003 per gallon. yours can't be too much more than that.

Carl

 

[little_squid]

thanks tgunn i like anthony calfo outlook on thinks

 

[RandyStacyE]

<a href=showthread.php?s=&postid=7378455#post7378455 target=_blank>Originally posted</a> by little_squid
i understand were randy is coming from but not all of the waste water imo is true waste!

I agree too, it's not 100% waste - it's just the nature of the unit itself to eject the waste with quite a bit of water with it.

 

[Roland Jacques]

little_squid
i think its a great idea. it would not work good in florida their water is too hard. but that would work great in Ga. are water is great out of the tap (30 - 50 tds) except for phosphates . i no this this being done in some industrial systems. i've heard of waste recovery systems sound like the samething.

 

[Charles99]

<a href=showthread.php?s=&postid=7378328#post7378328 target=_blank>Originally posted</a> by RandyStacyE
In a way it would be like trying to recycle the exhaust from your car by routing to the air box. It will screw up the engine.

This is done in most modern cars.

EGR Valve- Exhaust Gas Recirculation valve. Albeit, a small amount of exhaust is recirculated into the air intake. Basically a smog device.:bum:

 

[IslandCrow]

Truthfully, I just store my waste water and use it for other things, like laundry, washing the car, cooking, etc. I also have a hose attached to the side of the 33g waste water bucket, about 4/5 of the way up. When the bucket starts getting full, the excess water siphons off and waters my plants. Water's not particularly expensive where I live, but I hate wasting, and all in all, I end up not really wasting any water at all. If anyone's really curious what I'm talking about, I could post a picture.

 

[joedirt54]

What would be nice is a ro-waste water tub higher than your hot water heater. A float switch on the tub would trigger(open) a solenoid to add tap to the hot water heater when your ro waste was low. I think I'll do that.

The extra stuff might kill the water heater in time, but you'd pay for the waterheater 2x min when you add the cost of water. I just added $50 to my water bill in 3 months.

 

[Zan]

i think your membrane would be used up faster doing this.

 

[joedirt54]

why? The tub would only hold the water I would make using my ro/di...the rest would be tap...All I would be doing is dumping my waste water into my hot water heater.

The only thing I'd be wasting is the power to keep the soleniod open when I didn't have enough waste water to keep the hot water heater running.

What I could do is add a timer to the logic and only run the waste water additons in the morning.

 

[scrager]

i believe Zan was replying to the original idea in this thread.

your tub idea won't work because the waterheater is pressurized and is always full. it may not always be hot, but it is always full.

if you have a tub piped to the water heater supply the tub will fill from the supply line because the pressure in the line is greater than that in the tub.

if you disconnect the water heater supply and attach your tub, you won't get hot water in the house because the pressure is what pushes the water out of the heater and to your faucets.

 

[bryanth73]

little squid dumb question but is there an auto shut off on your ro unit im in the area with a 180 and my bills are about 1/3 of what your paying check to make sure its turnig off the waste water

 

[Roland Jacques]

If you run the same water by your membrane twice. (Hardness aside) the second time has almost the same effect on the membrane as the first. I believe the effect on the membrane is far less than 1% deference than the first pass. (As long as your water has been pre filtered well.) Im not a math guy, but it seems that your membrane may be "used up/ damaged" way less than 10% sooner this way. That is probably why industrial unit that produce 1000s gph do it this way. Then again their membranes may be more heavy duty.

Im just kind of guessing here. But it seems if you want to do this (and am going to try this,) a lower efficiency membrane may be in order

 

[landragon]

There are already loop set ups on the market. They take the waste directly and replumb it into the input with a second booster pump, and a solenoid valve on a timer to flush the membrane periodically. They are newer and I once asked the guys at spectrapure about this. His answers were less than hopeful about long term eficiency. I personally take my waste and water my lawn, or fill my washer with it. That way it is not wasted. If you have very hard water coming in, I suggest you not fill your washer. I understand this is not possible for apartment dwellers.