Slickdonkey
Drink me
Thanks Don, sounds like I've got a road map here to get this thing working again and lower my water bill.
RO/DI waste won't shutoff
- Thread starter Slickdonkey
- Start date
Help Support Reef Aquarium & Tank Building Forum:
Scooterman
Well-known member
Well that makes sense but Don if he is loosing pressure then he isn't making as much RO/Di water then he should only waste the same amount in relation to good pressure right? My thinking you waste only so much per gallon until filters get dirty and if you continually waste water then you must continually be making water right, If so where is this extra RO/DI water? It seems the switch is bad along with needing replacement filters.
Oh from before I was thinking a plumbing issue as in a clasped or bad restrictor, would that make sense? Also I was told the the 75gpd unit does last longer by Curt but you would have to ask him the reasons why I forgot!
Oh from before I was thinking a plumbing issue as in a clasped or bad restrictor, would that make sense? Also I was told the the 75gpd unit does last longer by Curt but you would have to ask him the reasons why I forgot!
DonW
R.I.P.
No, your not taking into concideration how the membrane functions. Concider a system that works just fine but the house pressure is low or the water is to cold. You end up with more waste and less ro effluent. Make sense?
Yes the 75gpd membranes are more efficient and two 75gpd membranes are very efficient. If you have the pressure dual membranes are the way to go.
Check out the filterguys.
Don
Scooterman
Well-known member
I fully understand that but even cold days with less pressure it still made produce water, I'm just wondering where it is going thats all?
DonW
R.I.P.
Down the drain. The ratio of clean water to dirty water changes based on pressure.
If your pre filters are plugged you loose not only pressure you loose flow. So basicly a reduction in waste and clean but its completly lopsided. The watse to clean ratio is going to be so high that there will not be enough pressure on the clean ouput to close the asv.
Most asv's require a minimum of 50 psi to shut down securely. Meaning they need any where from 33 to 45 psi at the clean water outlet. Good asv valves are usually the higher end so its more important to keep the prefilter clean if your supply only has about 60 psi.
The higher the pressure rating on the valve the less osmotic siphoning. Cheap systems use a 65% valve and better one use a 90% valve.
This is why most makers use a 65% valve, it gives you alot more time before having to change the prefilters. I use a 90% valve and its a pita but its a trade off for tds creep. I resorted to adding two pressure switches that trigger a buzzer when the asv does not shut down.
Does any of that babble make sense?
Don
Slickdonkey
Drink me
Good to know. So you run them in parallel after the prefilters? I'll look at the filterguys and see if I can figure it out. My house pressure is high (90psi or so) because there is no regulator on the house plumbing. Yeah I know I should have one put in one of these days.
Scooterman
Well-known member
Yea I like the idea of maybe having two 75gpd membranes!
I make my water in a 6g tank & carry it over to a holding tank for the top off unit. It would be much costly adding another line though the attic & down the wall & I don't think the ploy is mouse proof to use as long run through that attic, also & would have to rig another saddle valve into the water line & I already have one for the refrigerator, which I don't trust but it came with the house like that.
I make my water in a 6g tank & carry it over to a holding tank for the top off unit. It would be much costly adding another line though the attic & down the wall & I don't think the ploy is mouse proof to use as long run through that attic, also & would have to rig another saddle valve into the water line & I already have one for the refrigerator, which I don't trust but it came with the house like that.
DonW
R.I.P.
Run the poly line through 1/2 pvc in the atic, you should be able to leave open in the wall. Mouse proof
Don
wrightme43
Well-known member
I havent read the whole thread, so if this is answered already, tell me to shut up.
Which auto shutoff do you have. If it is a plastic square with 4 lines, two in two out. If you dont have a check valve at the good water output on the ro membrane it will never build the pressure to overcome incoming water pressure and it wont shut off the input water to the filter so it all just goes down the drain as waste water.
Which auto shutoff do you have. If it is a plastic square with 4 lines, two in two out. If you dont have a check valve at the good water output on the ro membrane it will never build the pressure to overcome incoming water pressure and it wont shut off the input water to the filter so it all just goes down the drain as waste water.
Slickdonkey
Drink me
Yep, that's the kind I have. As I mentioned before it was working fine for months so I suspect the filter is plugged. If the other suggestions don't work I'll look at the check valve; maybe it's broken.
Slickdonkey
Drink me
Well I placed an order for new prefilters but they were shipped via UPS ground from Florida so I should expect them about this time next year
In the meantime I did install a pressure gauge before the membrane and it reads 40psi. I'll have to measure the supply pressure tonight but if I recall it was around 80 or 90psi.
That's a neat idea. Did you document this in one of your threads somewhere? I'd be interested to see how you did this.
Slickdonkey
Drink me
I replaced the prefilters and ASV but I'm still getting lousy water output and lots of waste water. Could the membrane be clogged?
DonW
R.I.P.
Scooterman
Well-known member
Did you replace the flow restrictor, they can in rare cases collapse. I've only read this somewhere from Kent, it can happen. I usually peg over 60 psi before the membrane, maybe closer to 70.
Slickdonkey
Drink me
My pressure went up to 53 psi after I replaced the three prefilters (10/5/1 micron). I don't know if the ASV is working yet; I'll try to remember to test that tonight.
I did not replace the flow restrictor. However I am planning to move up to two 75gpd membranes and will replace it as part of that upgrade. I am a little worried I will need a booster pump though, since 60psi at the membrane seems to be the recommendation for this type of setup.
Scooterman
Well-known member
I still make good water at 45psi & little waste change, even with dirtier filters, yea the waste goes up but not drastic. Test the unit to see if it is working fine without the asv, then if it is yea you may need to boost it but that shouldn't be the case with 53psi!
DonW
R.I.P.
53psi should be fine, you made a big improvement with the prefilters but you may have trashed your membrane by running it with low pressure. 53psi is to low for a second membrane.
Don
Don
Slickdonkey
Drink me
What do you consider "low pressure"?
So next I will get a booster pump and hook up two 75 gpd membranes and replace the flow restrictor. After that I don't think there's much else I can possibly replace so that'd better do the trick!
DonW
R.I.P.
45 or less is harder on the membrane. You have to keep in mind when they rate the things it at the perfect temp (ours never is) and a regulated 60psi. IIRC 40 psi is the bare minimum for a dow membrane to function at all.
Don
Slickdonkey
Drink me
Don, what do you make of the fact that my incoming water pressure is 90psi before my first prefilter, and 53psi after passing through all three prefilters? That seems like a huge drop.
All prefilters are new. I'm using 10/5/1 micron in that order.
All prefilters are new. I'm using 10/5/1 micron in that order.
Similar threads
