Cryptic problem: RO membranes clog up. Please help
rajdude
Active Member
Well, I have been doing some research and calculations.
So far it seems to me that adding a water softener may be the only solution....or at the very least, the next possible "try-out".
After calculations, it becomes clear that a single big blue + resin will not last a whole week. I will need two. That means the cost doubles to around $250. Plus I feel it will be a chore to regenerate the cartridges every week.
So........the next thing to consider is a small capacity whole house water softener. That will regenerate automatically.
But I cannot find anything less than around $400. Well, that extra $150 may be worth it. Searching for a good deal, or a discount code or something.
Cheapest one is this which I see this at Home Depot
So far it seems to me that adding a water softener may be the only solution....or at the very least, the next possible "try-out".
After calculations, it becomes clear that a single big blue + resin will not last a whole week. I will need two. That means the cost doubles to around $250. Plus I feel it will be a chore to regenerate the cartridges every week.
So........the next thing to consider is a small capacity whole house water softener. That will regenerate automatically.
But I cannot find anything less than around $400. Well, that extra $150 may be worth it. Searching for a good deal, or a discount code or something.
Cheapest one is this which I see this at Home Depot
AQUASURE Harmony Lite Compact ALL-In-One 32,000 Grain Whole House Water Softener with Triple Purpose Pre-Filter AS-HL32C - The Home Depot
Indulge yourself with the luxury of spa-quality softened water The AQUASURE AS-HL34A was designed and built to provide soft, scale/spot-free water for the entire home. The system can treat up to 32,000
www.homedepot.com
rajdude
Active Member
@rajdude Maybe this membrane would be worth a try FilmTec Aqualast 1812-HR It looks like anti-scaling was part of the design criteria.
Thanks for this tip! I was not aware of this product.
So I did some research on this. I see two problems if I try to go this route:
1. Dupont says it will last 2 times longer.
That means in my system it may foul in 2 weeks (the usual membrane I put in fouls in 1 week)
2. I cannot find it anywhere on the 'net to purchase.
Maybe it is a "special order" item.
rajdude
Active Member
Water softener research:
Well, the more I learn about water softeners, the more it appears to me that it will cost me an arm and a leg to get a good one.
The cheaper ones (around $400) have two issues:
1. The Aquasource model I was considering at $370 has a pretty low salt efficiency ratings, less than 3200 grains / lb salt
Meaning it will use a lot more salt and water for regeneration. Although I do see an AO Smith model at Lowes for $420 whose rating is pretty nice, at 5210.
2. Capacity
They recommend going with the 45000 grain model for my house and water condition, which increases the cost to $620...
3. Chlorine treatment
On top of it, they highly recommend putting a carbon filter before the water softener, because the chlorine and chloramines in my water will damage the resin prematurely. So that adds at least $310 for a AO smith whole house model, like this one:
Also it will need to be replaced every 5-6 years.
Hence to do this, I will be out $1000 :-( Ummm........that is a little too rich for my pocket right now.
Well, the more I learn about water softeners, the more it appears to me that it will cost me an arm and a leg to get a good one.
The cheaper ones (around $400) have two issues:
1. The Aquasource model I was considering at $370 has a pretty low salt efficiency ratings, less than 3200 grains / lb salt
Meaning it will use a lot more salt and water for regeneration. Although I do see an AO Smith model at Lowes for $420 whose rating is pretty nice, at 5210.
2. Capacity
They recommend going with the 45000 grain model for my house and water condition, which increases the cost to $620...
3. Chlorine treatment
On top of it, they highly recommend putting a carbon filter before the water softener, because the chlorine and chloramines in my water will damage the resin prematurely. So that adds at least $310 for a AO smith whole house model, like this one:
Also it will need to be replaced every 5-6 years.
Hence to do this, I will be out $1000 :-( Ummm........that is a little too rich for my pocket right now.
rajdude
Active Member
Wait, I do see one reasonable option:
Get that $370 Aquasource softener and just use it for the RO filter (not for whole house).
The RO filter system already has chlorine + chloramine pre-filters. I could hook up the softener just before the membrane.
Get that $370 Aquasource softener and just use it for the RO filter (not for whole house).
The RO filter system already has chlorine + chloramine pre-filters. I could hook up the softener just before the membrane.
rajdude
Active Member
Well, I am still stumped, The system has fouled up again.
Do you have any experience and/or recommendations regarding anti scalants?
I mean what should I buy?
I could use a dosing pump, like is used in the hobby here.
I found some info here
sneekapeek
Active Member
I’m not saying buy this one exclusively. Just something I’ve googled real quick.
Antiscalant for RO Membranes | Anti-scale Water Additive | 5 Gallon Container | AMI
AMI AS-102 is a broad spectrum antiscalant designed for use with commercial and industrial membrane water treatment systems to inhibit the formation of calcium carbonate scale. Same-day shipment for all stock orders placed before 3pm.
direct inject into concentrate flow through membrane at a rate given flow. The stuff is a bit expensive up front but a little goes a long way! Just a few google searches will give you the jist of info. Just want it to be in there in the membrane chamber so most of the scale disperses down drain and not crystalize or form on exterior of membrane. I wouldn’t know how much to put in because each antiscalent is different based off potency. This is an option if you go down that route. Ideally you want everything automated and you would need electrical to do so. Mechanical floats won’t be able to stop the dosing off antiscalent.
sneekapeek
Active Member
Just run this and see if it works! Should help regardless.
rajdude
Active Member
I’m not saying buy this one exclusively. Just something I’ve googled real quick.
Antiscalant for RO Membranes | Anti-scale Water Additive | 5 Gallon Container | AMI
AMI AS-102 is a broad spectrum antiscalant designed for use with commercial and industrial membrane water treatment systems to inhibit the formation of calcium carbonate scale. Same-day shipment for all stock orders placed before 3pm.wateranywhere.com
direct inject into concentrate flow through membrane at a rate given flow. The stuff is a bit expensive up front but a little goes a long way! Just a few google searches will give you the jist of info. Just want it to be in there in the membrane chamber so most of the scale disperses down drain and not crystalize or form on exterior of membrane. I wouldn’t know how much to put in because each antiscalent is different based off potency. This is an option if you go down that route. Ideally you want everything automated and you would need electrical to do so. Mechanical floats won’t be able to stop the dosing off antiscalent.
Thanks! So if I wanna go this route, I need these two things:
1. Anti scalant.
I found a cheap ($50) bottle here:
Hyper-Guard Plus 7000 RO Scale Inhibitor - Maximize RO System Efficiency
Prevent costly scale damage with Hyper-Guard Plus 7000, the advanced RO scale inhibitor designed for prolonged membrane life and reduced operation costs in commercial RO, NF, and UF systems.
www.uswatersystems.com
2. A dosing pump
Ok this is probably not as straightforward as I thought, or maybe it is. I could buy a simple Peristaltic dosing pump and run it using my raspberry Pi RO water controller system (which I am building). $13 here
BUT my main concern is this: Can this peristaltic dosing pump fluid into RO lines which have house water pressure (around 70 psi)? A little bit of research says that some models of these pumps may be able to do 125psi! Hmmm....
Advantages of Peristaltic Pumps in Metering Applications
Peristaltic metering pumps, a type of positive displacement pump, are excellent at pumping dirty fluids that contain particulate matter into lower pressure systems because they have no check valves to clog.
www.pumpsandsystems.com
But this one says different:
How much pressure can a peristaltic pump normally reach? for Sale
Peristaltic pump pressure, high peristaltic pump pressure
So that is like 36 and 87 PSI. I bet that el-cheapo pump I linked above has a hose wall thickness less than 2.4 mm
Here are some pumps which may generate higher pressure...
peristaltic-pump
So the search goes on.........
rajdude
Active Member
ok I found one pump, but it is an expensive one.... Stenner pump. Apparently people use this type of pump to pump chlorine into their house supply lines (?). It is rated for 100psi
At $360 new it is way beyond my budget. eBay has it selling for $200, still too high.
Maybe I can get only its head part and add a stepper motor to it?
Head part is available for $90 on eBay. Guessing it will need a stepper motor with a lot of torque.
At $360 new it is way beyond my budget. eBay has it selling for $200, still too high.
Maybe I can get only its head part and add a stepper motor to it?
Head part is available for $90 on eBay. Guessing it will need a stepper motor with a lot of torque.
sneekapeek
Active Member
Yes they have a bit of problem with pressure and generally people who go this method justify costs. Check valve and a tee to supply membrane. I’d look into water softener, a small unit first. And if that doesn’t work then how badly do you want purified water
rajdude
Active Member
so while taking a shower yesterday, I thought about a viable solution to my injection problem.. LOL
Just use a container to dose anti-scalant into and then use a pump to suck water out of that container to send to the RO membrane. Done.
Please I get the advantage of being able to control the temperature of that water. Just put an aquarium heater in that container. That will ensure that the RO water system does not get fed with almost freezing water in the winter.
Now, to do that, I need a pump. Looked at RO booster pumps from Aquatec. They run around $85. I called them yesterday (left a message) to find out if they can pull from a bucket (0 psi input) and still generate 80 psi. Waiting for a call back. From what I have read, these pumps need a little bit of pressure at their input. BRS says that they "add" pressure to say a 20-30 psi input and end up at 80psi.
Maybe I could use a demand pump instead.
As for dosing pump, the $10 pump I mentioned earlier + my Raspberry Pi based controller will work fine.
Just use a container to dose anti-scalant into and then use a pump to suck water out of that container to send to the RO membrane. Done.
Please I get the advantage of being able to control the temperature of that water. Just put an aquarium heater in that container. That will ensure that the RO water system does not get fed with almost freezing water in the winter.
Now, to do that, I need a pump. Looked at RO booster pumps from Aquatec. They run around $85. I called them yesterday (left a message) to find out if they can pull from a bucket (0 psi input) and still generate 80 psi. Waiting for a call back. From what I have read, these pumps need a little bit of pressure at their input. BRS says that they "add" pressure to say a 20-30 psi input and end up at 80psi.
Maybe I could use a demand pump instead.
As for dosing pump, the $10 pump I mentioned earlier + my Raspberry Pi based controller will work fine.
Last edited:
rajdude
Active Member
Yes they have a bit of problem with pressure and generally people who go this method justify costs. Check valve and a tee to supply membrane. I’d look into water softener, a small unit first. And if that doesn’t work then how badly do you want purified water
Yeah, I thought more about the water softener option but I see two issues if I go that route:
1. No guarantee that soft water will resolve my membrane fouling problem.
It seems to me it may be something more than just hard water which is fouling my membranes. The water report (attached) shows some silicon (silica) , magnesium and potassium which is higher than the EPA limits.
I suspect injecting anti-scalant will probably take care of whatever is in my water which is precipitating onto my membrane.
2. Difficult to install.
I looked at my home's water lines, it is difficult to install a softener here. The problem is that they have buried the city water input behind drywall (There is a shut off access door). But right after that, they have run the lines to front outside spigot, then kitchen, then backyard spigot, then upstairs bathrooms, and THEN the lines come to the unfinished area where I could possibly put the whole house water softener :-(
Yeah, I could use the $400 water softener for ONLY the RO water filter, but I feel that is an overkill.
Maybe my other idea (see previous post) will cost me around $150 and gives me a greater chance of success.
sneekapeek
Active Member
Water softener would really do the trick as well. Honestly I’d pick up a cheap bag of sodium based pellet, put in one of your blue housings. Run RO unit to fill. Open the next time you go to use to see how much disintegrated. Calculate and fill every time you need. Or buy proper housing for unit. Usually antiscalent in commercial uses as last resort.
rajdude
Active Member
ok folks, here is an update:
I bought a bunch of things:
Then I changed my system so that it looks like this:
Inlet > Shutoff valve > pressure gauge > sediment 1 micron > carbon 1 > carbon 2 > sediment 0.5 micron > pressure gauge > flow control valve > float valve > Brute drum
The flow control valve is set to reduce flow to 1 quart per minute. The idea is to increase the time of contact of water with activated carbon so as to adsorb chloramines.
From Brute drum > Booster pump > one way valve > membrane > Tee >
The booster pump is able to suck water from the drum and run the RO system at around 85 PSI. My waste to product ratio is 1:1 right now. Why so low? Well, the membrane gets fouled with silt/junk in a week anyway, so why bother wasting water.
I am currently doing an acid bath on the membrane weekly to maintain flow. I actually have a second housing for feeding acid via a two way valve (gotta post a photo and a diagram).
However, the whole point of this setup was to add anti-scalant to the feed water (in the drum). Also gives me a chance to heat the water in the winter.
I have my eyes on this one. But first I am trying to figure out how much do I need to add to the 30 gallon drum. That is the quantity of water I run through the RO filter in one "run".
Overkill? Oh yeah! Big time overkill, baby!
I bought a bunch of things:
- Aquatec booster pump - AQUATEC 8851 SERIES RO BOOSTER PUMP 24VAC 8851-2J03-B421 + TRANSFORMER
- 30 gallon Brute drum
- Another housing with a 0.5 micron sediment filter (post carbon blocks)
- Flow control valve (this one)
Then I changed my system so that it looks like this:
Inlet > Shutoff valve > pressure gauge > sediment 1 micron > carbon 1 > carbon 2 > sediment 0.5 micron > pressure gauge > flow control valve > float valve > Brute drum
The flow control valve is set to reduce flow to 1 quart per minute. The idea is to increase the time of contact of water with activated carbon so as to adsorb chloramines.
From Brute drum > Booster pump > one way valve > membrane > Tee >
> one way valve > aquarium water drum
> one way valve > drinking water drum
The booster pump is able to suck water from the drum and run the RO system at around 85 PSI. My waste to product ratio is 1:1 right now. Why so low? Well, the membrane gets fouled with silt/junk in a week anyway, so why bother wasting water.
I am currently doing an acid bath on the membrane weekly to maintain flow. I actually have a second housing for feeding acid via a two way valve (gotta post a photo and a diagram).
However, the whole point of this setup was to add anti-scalant to the feed water (in the drum). Also gives me a chance to heat the water in the winter.
I have my eyes on this one. But first I am trying to figure out how much do I need to add to the 30 gallon drum. That is the quantity of water I run through the RO filter in one "run".
Overkill? Oh yeah! Big time overkill, baby!
rajdude
Active Member
OK so I have been scratching my head over this and and finally called and talked to Jeff at King Lee about dosage of their product (this is the same thing being sold here for $50 for a 32 oz bottle):
He said use 5-10 ppm as a starting point
Calculation:
So that is 0.005 ml / liter
The 30 gallon Brute probably holds 28 gallons, up to the fill line which is = 105 liters
So I should add 0.005 x 105 = 0.525 ml to this drum
If I wanna do 10 ppm, it will calculate to 1 ml
That tiny amount will work as anti scalant?
He said use 5-10 ppm as a starting point
Calculation:
So that is 0.005 ml / liter
The 30 gallon Brute probably holds 28 gallons, up to the fill line which is = 105 liters
So I should add 0.005 x 105 = 0.525 ml to this drum
If I wanna do 10 ppm, it will calculate to 1 ml
That tiny amount will work as anti scalant?
There are a couple of ways to identify a bad RO membrane such as discoloration, sudden decrease in the flow rate, foul taste or smell, lukewarm water, and cloudiness in the membrane.
There’s nothing much you can do about a bad membrane, either. There’s only one solution to all of these problems: replacing them.
There’s nothing much you can do about a bad membrane, either. There’s only one solution to all of these problems: replacing them.
Cobra1365
New Member
At the risk of hijacking your thread…
I’ve read entry run into a situation with my drinking water RO system. The pre filters clog within a month and the system stop producing. I cut open a pre filter yesterday and it was coated with a white slime that looked like silicone grease.
I already have a 5 micron spin down, a 10 micron sediment and a carbon block all BEFORE the RO system. None of which show any slime build up.
From those three filters, the water flows into a soda ash system which consists of a 15 gallon tank where the soda ash mixes with water and is drawn from By a stunner pump activated by useage demand. Then it goes to a holding tank Where it mixes with household water.
1) What would that slime be?
2) Why only on the RO system
3) is there something I could add to the Soda Ash tank to eliminate it?
BTW, MY RO system is an ECO Water 375 and has sealed filter canisters. So, no way to do periodic cleaning other than replace filters at $70 a pop!
I’ve read entry run into a situation with my drinking water RO system. The pre filters clog within a month and the system stop producing. I cut open a pre filter yesterday and it was coated with a white slime that looked like silicone grease.
I already have a 5 micron spin down, a 10 micron sediment and a carbon block all BEFORE the RO system. None of which show any slime build up.
From those three filters, the water flows into a soda ash system which consists of a 15 gallon tank where the soda ash mixes with water and is drawn from By a stunner pump activated by useage demand. Then it goes to a holding tank Where it mixes with household water.
1) What would that slime be?
2) Why only on the RO system
3) is there something I could add to the Soda Ash tank to eliminate it?
BTW, MY RO system is an ECO Water 375 and has sealed filter canisters. So, no way to do periodic cleaning other than replace filters at $70 a pop!
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