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How many Gpd ?

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Dan Paton

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Glasgow
Silly question but one that's bugging me. Is there any way other than setting this ro system up to tell what the gpd is? It's one I got second hand and it's been collecting dust in the garage. There's no brand name or anything that gives any indication cheers .
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Hi there I am no expert, but if you pull the ro mems out then they will no dout say, then just add up each one.

 
Hi Dan,

If its been lying around the possibility exists that the membranes have dried out which renders them useless.

We used to refer to these as RoMan type r/o's. There was a couple of variants to the way they were sold with regard to the 3 prefilters that are part of the r/o. The first one is a sediment filter and the second will be a carbon block filter to remove chlorine from the water. The third could either be a GAC filter (not needed for window cleaning) or a small resin vessel to polish the remaining tds from the pure produced by the r/o.

To start with the prefilters are 10".  I'm not totally sure what the lone prefilter housing is on the very left of the photo, but it could be a water softner so could be filled with softener salt. I don't honestly know. (When I had my original 450GPD r/o I added a couple of additional 10" resin cartridges, so there is the possibility that the original cleaner did the same.)

The membranes are available in different GPD's. The housing will fit any of the following, 50, 75, 100, 125 and 150GPD membranes. So as @The window cleaning kidresponded, the only way to see what they are is to take one out.

What would I do? I would unscrew each of the prefilters and see what you have. For window cleaning we only need 2 prefilters, a sediment and a carbon block. These are available from most suppliers. My preference is for Fiberdyne carbon block prefilters from Gardiners. I'm happy with their performance. They are 5 micron and as this is the same as the sediment filter the Fiberdyne won't block up. If gives a good service life 38,000 liters which includes waste and pure. There are other carbon block filters on the market with a much longer service life, but at 1 micron will tend to clog up with fine dirt before their service cycle is complete if your water is anything like ours. )

http://gardinerpolesystems.co.uk/all-products/pure-water-systems/water-treatment/sediment-carbon-filters/fibredyne-cfb-plus-sediment-carbon-pre-filter-10.html

sediment

http://gardinerpolesystems.co.uk/all-products/pure-water-systems/water-treatment/sediment-carbon-filters/sediment-pre-filter-10.html

I would run the r/o and see what happens. You need to set it up so you have a waste to pure water ratio of about 1 to 1. This means that water must go to waste at the same time you are make pure. I 1 to 1 ratio is 1 liter of waste water to 1 liter of pure produced.

To tell if your membranes need replacing is simple. You know your tap water tds so write that down. Let you r/o run for an hour or so just to let it bed itself in and then test the pure coming out of the membranes before the resin filter. Ideally this pure output should be around 2 or 3% of the tap water tds. (So you would expect the membranes to remove between 97 and 98% of the dissolved solids in the water. So if your tap water tds is 200 the pure water coming out of the membranes should be between 4 and 6ppm. If its any higher than that then you need to replace the membranes. They estimate that you should seriously consider replacing membranes when the efficiency of them drops to 94%. In our example, that's 12ppm. The lower the efficiency to more resin you will use polishing the water off.)

There is a very recent post this last weekend that may also help you a bit.

https://windowcleaningforums.co.uk/topic/22486-ro-question/

If you have to replace membranes, then go for a good quality manufacturer. I would replace them with 150gpd membranes as they will produce water the quickest. But please bear in mind that they are all very slow.

@doug atkinsonsupplies good 150GPD membranes.

http://www.daqua.co.uk/reverseosmosis.htm

Aexon are a little more expensive but are the best.

I hope that helps.

 
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Thank you Spruce That's every query I had answered. Your help is much appreciated. Cheers


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Thank you Spruce That's every query I had answered. Your help is much appreciated. Cheers


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Even with 3 x 150gpd membranes these r/o will produce water very slowly - painfully slowly is probably a better expression.

Once you have your r/o up and running I would suggest you invest in a used 1000 liter IBC tank and process your pure water into that. It would take between 28 and 36 hours to fill our IBC tank with pure but these will give you plenty of reserve when full. It will mean that you will also need a submersible transfer pump to fill the van's tank when you need water.

We tried to process water directly into one of Peter Fogwill's trailers I originally owned, but it just didn't work. I couldn't believe how much easier life became when I bought a clean used IBC tank.

 
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As just stated, it is a slow system, mine is 300 gpd and takes probably 12-15 hours to fill my 600 ltr ibc tank, but as it's a storage tank in my garage it doesn't matter. Also, Spruce is right to a degree, the 3 lower vessels are 3 pre filters, probably don't need the 3rd one but I use it anyway as it doesn't hurt, the 3 smaller vessels above are the membranes, as mentioned get the membranes out to see there output (gpd). The extra vessel on the left is the resin vessel. I binned mine off and bought a 10 ltr resin vessel to save having to change 1 ltr one more often.


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As just stated, it is a slow system, mine is 300 gpd and takes probably 12-15 hours to fill my 600 ltr ibc tank, but as it's a storage tank in my garage it doesn't matter. Also, Spruce is right to a degree, the 3 lower vessels are 3 pre filters, probably don't need the 3rd one but I use it anyway as it doesn't hurt, the 3 smaller vessels above are the membranes, as mentioned get the membranes out to see there output (gpd). The extra vessel on the left is the resin vessel. I binned mine off and bought a 10 ltr resin vessel to save having to change 1 ltr one more often.


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TBH I wouldn't even bother to go that far. If he took them out and saw they were 100gpd membranes OK, then what? He will know his r/o is a 300gpd but that doesn't mean much imho.

If @Dan Patonthen believes he will get 300gpd from his r/o he will find that he won't. As stated on the previous thread linked the 'day' quoted is 24 hours. The specs were done by the manufacturer at the optimum pressure and incoming water temperature to achieve those performance results. Its also an American gallon which is smaller than an imperial gallon at 4 liters. Our experience is that we can only expect about 1/2 the amount the membrane specification states, a little less when the water is colder in winter.

If his water is 'clean' then he could remove the sediment filter and just run a carbon block. Unfortunately our water is sometimes laden with sediment and I have to replace 3 sediment filters to 1 Fiberdyne carbon block filter. My filter has processed 10,000 liters so far this prefilter change and the sediment filter is already clogging up. My 20" Fiberdyne filter should be good for over 75,000 liters. 

I personally would work with as few prefilters as I need. It probably won't make much of a difference on a small r/o, but we need all the flow and pressure without restrictions on a larger r/o. An extra prefilter that's not necessary is an added restriction.

.

 
As just stated, it is a slow system, mine is 300 gpd and takes probably 12-15 hours to fill my 600 ltr ibc tank, but as it's a storage tank in my garage it doesn't matter. Also, Spruce is right to a degree, the 3 lower vessels are 3 pre filters, probably don't need the 3rd one but I use it anyway as it doesn't hurt, the 3 smaller vessels above are the membranes, as mentioned get the membranes out to see there output (gpd). The extra vessel on the left is the resin vessel. I binned mine off and bought a 10 ltr resin vessel to save having to change 1 ltr one more often.


Sent using the [mention=2421]Dan Paton[/mention]then believes he will get 300gpd from his r/o he will find that he won't. As stated on the previous thread linked the 'day' quoted is 24 hours. The specs were done by the manufacturer at the optimum pressure and incoming water temperature to achieve those performance results. Its also an American gallon which is smaller than an imperial gallon at 4 liters. Our experience is that we can only expect about 1/2 the amount the membrane specification states, a little less when the water is colder in winter.
 
If his water is 'clean' then he could remove the sediment filter and just run a carbon block. Unfortunately our water is sometimes laden with sediment and I have to replace 3 sediment filters to 1 Fiberdyne carbon block filter. My filter has processed 10,000 liters so far this prefilter change and the sediment filter is already clogging up. My 20" Fiberdyne filter should be good for over 75,000 liters. 
 
I personally would work with as few prefilters as I need. It probably won't make much of a difference on a small r/o, but we need all the flow and pressure without restrictions on a larger r/o. An extra prefilter that's not necessary is an added restriction.
 
.
Too true Spruce, fair point well made lol I was talking more about the set up when I said you were right to a degree, you weren't too sure about the extra housing added on, I have the same system just from pure freedom and that extra vessel is for the resin, I was just informing Dan of that. I might drop my 3 Rd filter if it doesn't need it, never really looked into it [emoji3] the prefilters are only there to protect the membranes aren't they?


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Too true Spruce, fair point well made lol I was talking more about the set up when I said you were right to a degree, you weren't too sure about the extra housing added on, I have the same system just from pure freedom and that extra vessel is for the resin, I was just informing Dan of that. I might drop my 3 Rd filter if it doesn't need it, never really looked into it
emoji3.png
the prefilters are only there to protect the membranes aren't they?


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Yes that correct. The carbon block is by far the most important one as it removes chlorine. Chlorine and membranes aren't good bosom buddies. :1f609:

I honestly didn't know what the loose filter was. You input will help Dan. That's the reason for this forum, to help each other. You could very well be right to it being a di vessel as it would appear the resin is lighter at the top than it is at the bottom. Our little di vessel had resin in cartridges that we took out of the housing, emptied, refilled and replaced back inside. At a glance we couldn't see the resin changing colour as it became more and more spent. We had to keep testing our product water with our tds meter.

There is a pipe connector on the pipe into the loose di vessel on the left. It could add further to it being a small di vessel as the first user could 'remove' the vessel from the system when starting the r/o up to save his resin with tds creep.

But I did notice that the sediment filter looks very clean. As I have only our filters to compare it with, I would say that the sediment filter is new which might lead me to believe the carbon block was also replaced just before Dan bought it. (I would still replace them anyway though.)

.

 
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Yes that correct. The carbon block is by far the most important one as it removes chlorine. Chlorine and membranes aren't good bosom buddies. /emoticons/1f609.png
I honestly didn't know what the loose filter was. You input will help Dan. That's the reason for this forum, to help each other. You could very well be right to it being a di vessel as it would appear the resin is lighter at the top than it is at the bottom. Our little di vessel had resin in cartridges that we took out of the housing, emptied, refilled and replaced back inside. At a glance we couldn't see the resin changing colour as it became more and more spent. We had to keep testing our product water with our tds meter.
 
There is a pipe connector on the pipe into the loose di vessel on the left. It could add further to it being a small di vessel as the first user could 'remove' the vessel from the system when starting the r/o up to save his resin with tds creep.
 
But I did notice that the sediment filter looks very clean. As I have only our filters to compare it with, I would say that the sediment filter is new which might lead me to believe the carbon block was also replaced just before Dan bought it. (I would still replace them anyway though.)
 
.
I've got a question for you Spruce, you seem to be a man in the know [emoji3] the only issue I've ever had with my system is my rejection rate, not too clever. Ever since I bought the system the tds coming out of membranes before resin is between 32 and 35. I've had System a year and a half, just changed membranes as crept up to 42. Now lowest I can get again is 32 ppm. So I use a fair bit of resin. I've just got round to purchasing a pressure gauge to see if it is water pressure, could well be a pressure issue and need a booster. But if I dropped the 3rd pre filter, would taking a little bit of restriction away before the membranes possibly help with my issue?


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I have a 450gpd and i now only use the 1 pre filter

It seems to make a difference 

Not enough to dramatically reduce production time but it is seeming to fill 400l about an hour quicker as i can go to work with it empty in the morning and come home early afternoon to another 400l waiting for me

 
I've got a question for you Spruce, you seem to be a man in the know
emoji3.png
the only issue I've ever had with my system is my rejection rate, not too clever. Ever since I bought the system the tds coming out of membranes before resin is between 32 and 35. I've had System a year and a half, just changed membranes as crept up to 42. Now lowest I can get again is 32 ppm. So I use a fair bit of resin. I've just got round to purchasing a pressure gauge to see if it is water pressure, could well be a pressure issue and need a booster. But if I dropped the 3rd pre filter, would taking a little bit of restriction away before the membranes possibly help with my issue?


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It's always worth a try. You could remove the sediment filter as well for a bit.

If you have just changed membranes then something isn't right. Low water pressure doesn't help. But it worth testing the output of each membrane to check incase one of them is the issue.

The pure from each membrane will be joined together before heading off to your resin vessel and storage tank.Just run your r/o as normal but take each pure water pipe off the t piece so you can catch a sample of pure from the membrane to test it with your tds meter. Do this with each of your pure membranes. If they are all the same then chances are its pressure related.

If one of them has a rogue reading then you have water from that membrane contaminating the pure from the other 2.

If this is the case then you also need to check that you haven't confused the waste outlet with the pure outlet which is easily done.

You can easily tell which is the pure and waste outlet pipes. If you remove both pipes and run the system you will get a jet of water from the waste outlet and a few drops from the pure outlet.

If you look carefully, the waste outlet comes from the center of the housing and the pure is just off from the center.

It could also be that the membrane needs removing and reseating. It's good to put a thin smear of silicone grease on the rubber o rings so they slide into the housing easier.

What membranes did you buy?

.

 
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It's always worth a try. You could remove the sediment filter as well for a bit.
 
If you have just changed membranes then something isn't right. Low water pressure doesn't help. But it worth testing the output of each membrane to check incase one of them is the issue.
The pure from each membrane will be joined together before heading off to your resin vessel and storage tank.Just run your r/o as normal but take each pure water pipe off the t piece so you can catch a sample of pure from the membrane to test it with your tds meter. Do this with each of your pure membranes. If they are all the same then chances are its pressure related.
If one of them has a rogue reading then you have water from that membrane contaminating the pure from the other 2.
 
If this is the case then you also need to check that you haven't confused the waste outlet with the pure outlet which is easily done.
 
You can easily tell which is the pure and waste outlet pipes. If you remove both pipes and run the system you will get a jet of water from the waste outlet and a few drops from the pure outlet.
If you look carefully, the waste outlet comes from the center of the housing and the pure is just off from the center.
It could also be that the membrane needs removing and reseating. It's good to put a thin smear of silicone grease on the rubber o rings so they slide into the housing easier.
 
What membranes did you buy?
 
.
 
 
Cheers I will try all that, some good advice. I'm pretty sure all the pipes are connected right as I labelled them up but I will double check. Even when the system was new a year and a half ago the lowest I ever had it was 32 tds, that was with original membranes and it was set up from pure freedom. At the time I thought that was normal but speaking to others in my area it seems quite high, they are getting between 10 and 15 tds from filters. I got the membranes from Collins Water in Sheffield.


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Cheers I will try all that, some good advice. I'm pretty sure all the pipes are connected right as I labelled them up but I will double check. Even when the system was new a year and a half ago the lowest I ever had it was 32 tds, that was with original membranes and it was set up from pure freedom. At the time I thought that was normal but speaking to others in my area it seems quite high, they are getting between 10 and 15 tds from filters. I got the membranes from Collins Water in Sheffield.


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I rate the product from PureFreedom highly. There are a couple of window cleaners locally who sing their praises. But there is always the possibility that someone at PF could have also made a mistake during assembly and you inadvertently replicated it by your attention to detail. It seems strange that the r/o has performed well below spec since you purchased it.

I however would be a little hesitant about the membranes you purchased from Collins. They are of Asian manufacture and don't have the same performance or lifetime expectations of the Axeon membranes that are manufactured in the States.

They used to sell Vitron membranes which were a lower spec than Axeon but now they sell HID membranes made in China.

They are cheaper than the Axeon membranes that http://www.daqua.co.uk/roproducts.htm sell, but I'm a great believer that you get what you pay for.

.

 
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I've got a question for you Spruce, you seem to be a man in the know
emoji3.png
the only issue I've ever had with my system is my rejection rate, not too clever. Ever since I bought the system the tds coming out of membranes before resin is between 32 and 35. I've had System a year and a half, just changed membranes as crept up to 42. Now lowest I can get again is 32 ppm. So I use a fair bit of resin. I've just got round to purchasing a pressure gauge to see if it is water pressure, could well be a pressure issue and need a booster. But if I dropped the 3rd pre filter, would taking a little bit of restriction away before the membranes possibly help with my issue?


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I'm having the exact same problem as you. I've got a PF 40/40, pressure has dropped through the floor from 40psi to around 20psi. Tap psi going in is 38psi. TDS coming out of RO is up to 044PPM. Spruce, Kev and myself are trying to solve this problem before I go out and purchase something expensive. I've tried boosting input using a Shurflo pump. Psi went up to 22psi and TDS came down slightly.

Grrrr

 
I've got a question for you Spruce, you seem to be a man in the know
emoji3.png
the only issue I've ever had with my system is my rejection rate, not too clever. Ever since I bought the system the tds coming out of membranes before resin is between 32 and 35. I've had System a year and a half, just changed membranes as crept up to 42. Now lowest I can get again is 32 ppm. So I use a fair bit of resin. I've just got round to purchasing a pressure gauge to see if it is water pressure, could well be a pressure issue and need a booster. But if I dropped the 3rd pre filter, would taking a little bit of restriction away before the membranes possibly help with my issue?


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Measure your waste vs pure. Should be around 60 /40.

It sounds like your not get enough back pressure on the membranes so the R/O could be configured wrong or wrong flow restrictor.

 
Cheers for all the suggestions and advice, I am going to have a good look at the system over the weekend and do the tests to see if it is a dodgy membrane or a wrong connection etc. I don't doubt pure freedom stuff but maybe there is something a Miss somewhere, otherwise it must be pressure. And yes tuffers it is very frustrating. Unfortunately for me it's been like this from the beginning but I didn't realise I thought it was normal. But hopefully I can get on top of it [emoji106] cheers again [emoji106][emoji106][emoji106]


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I know I've nudged in on Dans thread but I wanted to thank everyone who gave me advice on my tds issue. As it was a rainy day today I decided to do the tests on it. Firstly check all the tubes were connected to the right places, thankfully they were, so pure and waste wasn't getting mixed up. Next the membranes. Tested the tds from each one, one was 16, one was 22, one was 62 [emoji50] so there was my issue. So I took it out, gave the casing a good clean and put it back in making sure it was sat correctly, after about 30 seconds of running the tds from that one was down to 20 [emoji122] it must not have been sat in correctly. Now I'm getting a tds of around 16-17 from my system before RO. Much happier! Can't believe after a year and a half I've got it right. Don't know if it was same issue with original membranes. Thanks to spruce I think it was your suggestion to check membranes seated correctly!


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