Clean It Up
UK Window Cleaning Forum => Window Cleaning Forum => Topic started by: Fieldsy on August 12, 2009, 05:44:29 pm
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Whilst I was running my little 100gpd through 2x 700ml DI units, i was capable of a tds of 000 from 350main, it has significantly got higher, so I decided to change and upgrade to 200gpd (to produce more), and bought some tulsion resin to replace in the two DI units.
Now, the tds is stable at 002, and won't go below. Am I expecting too much to get 000 from a 200gpd unit with only 2x700ml, and is 002 the best I can expect from this set up???
The original 100gpd membrane and filters are only about 6-7 weeks old. When should they be changed??
What I'm trying to say is, even if I changed the filters (which I wouldn't assume is due yet), is it still possible that the tds will stay at 002, because of twice the amount of water going through the two DI's
thanks
Fieldsy
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your tds will go down to 000 did you disconnect your di when you fitted the upgrade kit and run water through it for a while i normally do 25 ltrs of water when fitting a new membrane . then re connect the di .
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its been running for about 4 hours and still at 002, so that looks like where its going to stay :(
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350 going into the RO should come out at about 007. A cupful of resin will get that down to 0.
Disconnect the resin part, and take a TDS reading from the output of the RO.
Also, the more membranes you add the higher the water pressure needs to be. What pressure are you getting?
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If you ran the system with the new membrane straight through the resin then the high initial contam might have used up the resin.
I always bypass the resin when flushing a new membrane as I has similar to your problem once.
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Thanks Dan, just checked water from RO and its 025 ??
@John, when I initially connected the membrane, I ran the water for about 15-20 litres and got a tds of 011, so suspected the resin,so the membrane should have had a good flush. I've now changed the resin and still getting 002 ???
thanks
Fieldsy.
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so does anyone think that 25 from the RO is high ?? ???, could it be a filter change??
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so does anyone think that 25 from the RO is high ?? ???, could it be a filter change??
i dont think you need new filters mate , ive just checked mine and its 23 i only put new filters and membranes in last week my tap tds is 370 .
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Hi Dave,
well to cover all options, I replaced the filters and bugger me the tds is still 002 after running about 25 litres of pure ??? ??? ::) ::).
The resin is brand new, that only leaves the membranes.......and they can't be knackered yet surely??
One thing I have noticed, the second DI in sequence is taking bloody ages to fill once its passed through the first. The first fills up in no time, the second takes a good half hour to fill up???. I know this wouldn't have an effect on the tds....but weird why its taking so long.................it filled up in no time when I originally set the system up. Since changing the resin, the second takes ages??
cheers
Fieldsy
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you need a water pressure of around 65 psi or more to get the results you want
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I have an 85psi booster pump, I thought that would be sufficient???
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you need a water pressure of around 65 psi or more to get the results you want
mikes right,
my ro-man 200gpd ro is over 2 years old, same membranes, change the filters every 6 mnths,
my tds is around 600 and the ro will still knock that down to 8, but i use a booster pump at 85 psi
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I have an 85psi booster pump, I thought that would be sufficient???
should be more than enough there fieldsy
cannot understand what else could be the prob really :'(
try just using the first di and see what happens
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are they inferior membranes, where did you buy them from ???
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How do you have it set up? Do you have any pictures?
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membranes/system etc.... were bought from vyair, and it was running fine before introducing the 2nd 100gpd.
I'll upload a pic ;)
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looking forward to pics ;D
mind you a tds of 2 would not worry me fieldsy :o ;D
dont lose any sleep over it ;D
not heard of vyair before, good prices :)
regards
mike
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notice how the second di is still not full and thats been running for about 1.5 hours
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hmmm not sure , ime thinking air lock
but not sure,will look at mine 2 moro and get back to you
wheres andrew mcann when you want him ;)
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Hi Mike,
Would an air lock cause the problem, and if so whats the best way to release it. I filled the di cannisters with resin about 2 inches from the top. Should they have been packed to the brim??
thanks for all the advice.
Fieldsy
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i pack mine to the brim :o ::) ;D
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ok time for a little modification then...lol
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good luck and good night ;) ;D
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lol....well good and bad news, filled them to the brim and second DI filled up in no time, and took tds down..............................but!!!!, its still 001 !!!! think I can live with that...lol
g'nite ;) ....and thanks for the tip ;)
Fieldsy
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You sure your not running the waste pipe through the di units?
Can't tell from the pics.
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Hi
Go back to your original setup before you added the extra membrane. Disconnect the pure outlet from going through the resin and take a TDS reading after about half an hour. That reading should be about 97 - 98% of your input. ie TDS of 350 input should result in an output of around 7 or better. If this is correct then that membrane is ok. Then remove that membrane from the loop and plumb in the new membrane exactly as the first one. Run the system in exactly the same way as with the first one. Take a reading again and you will be able to see where the problem is. If it is with your new membrane try swopping the waste and pure outputs around and see if there is any difference.
Hope this helps
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Thanks Spruce, thats a handly liitle tip to keep in mind. After filling the DI units to the brim and restarting the system, the possible air lock has disappeared, the DI units filled immediately, and now the tds is down to 000 ;D. I'm a happy bunny ;)
thanks for everyones advice and tips, much appreciated.
Fieldsy
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As for the airlock in the resin cannister.- my setup is 5 years old, changed filters regularily, upgraded from 100gpd membranes to 150gpd 3 years ago and changed those about a year back. Each time I replace the resin in the cartridge I get an airlock like you. It hasn't caused any problems and will eventually clear.
I still think you should isolate those membranes and check their performance individually. If you are getting a high TDS output from either of them, then you are going to go through resin at a rapid rate.
I had a high TDS output with some old membranes and it was then that I ordered 150GPD membranes to replace them. Ro-man didn't have them in stock and had to wait about 10 days before they came. In that time I was replacing the resin in that single cannister every evening. The tds of the water in my van tank was slowly rising over that period, indicating that the resin probably needed to be changed twice a day.
Spruce
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Well, just under 2000 litres and the tds has shot up to 008 ????. I've tested it the way Spruce has suggested, the first original membrane is giving a tds of 013 and the new one when connected seperately is 011. When I join them , the resulting tds before DI is 020, and after DI 008. Anyone any suggestions what is going wrong. I only changed the resin beginning of last week.
Where do you think the fault lies, the high tds from the ro or resin???. I bought Tulsion, and thought it would last longer, but the tds after the ro seems high, does it not ???
thanks
Fieldsy
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I think when you upgrade by adding a new membrane you need to alter the rejection rate via a restriction valve, I think there is info on the ro-man website. re the TDS rising rapidly the only reason it would do that is that you are hammering the new resin with high TDS do you disconnect the RO from the resin when you start producing pure? if not leave your RO over night then turn it on in the morning and straight away fill a tumbler of water pre DI, You will have a shock.
There is mention of the restricter here http://www.ro-man.com/shop/product_reviews_info.php/products_id/132/reviews_id/18?osCsid=044d261d4061e96c95fed5e5ecd0b447
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Hi Chris,
thanks for that, no I never disconnect it, should I ???. I just turn it on. So are you possibly saying the new resin is already "spoilt" by not disconnecting each time I turn it on??. So everytime I stop production of water, I should disconnect???
thanks
Fieldsy
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Yes that's what I do, I must admit I didn't use my 100gpd for long before upgrading to a 4040 but I did find the TDS was exceptionally high when I first turned it, and the 4040 does the same so I always run my RO for about 10 mins before I put it through the DI.
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ok Chris, thanks for the tip. I'll refresh the resin again ::), and try your method and see how I get on. thanks for the info. I'm still concerned that the tds is in the 20's from the two membranes, does this seem normal??
One more question??, are membranes of all the same standard??, for example is their a possibility that one make of membrane from a supplier could be inferior to another. I'm just wondering if the 011 and 013 I'm getting from them independantly is considered to be high???
thanks again
Fieldsy
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I'm no expert on RO's so can only quote what I have found, your TDS does sound high to me, and could be down to your rejection rate, on my RO if I set it at 60 pure and 40 rejected I have a tds of 12-14 If its the other way around I'm down to a TDS of 5.
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Just a thought - if you connect your membranes in parrallel and you have two different quality membranes (or one shot membrane) or even a poorly fitted membrane, would the majority of water pass through one more than the other?
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I've got a similar problem and I feel like I'm being taken for a bit of a mug by the company I bought it from.It's a 300gpd ro system which I was assured was excellent.My tds is high as well,330 or so but from the first time I used it it only brought the tds down to 030.The chap told me that the fact it's gone down by 300 proves that it's working.Fair enough I thought.I only window clean about 1 or 2 days a week at present and probably make 200 litres a week since I bought it 3 or 4 months ago.Now the tds reads high 060s and needless to say I'm going through resin in my DI like there's no tomorrow.Getting cheesed off with it frankly.Water pressure is very good and I always flush the system.
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"The chap told me that the fact it's gone down by 300 proves that it's working."
Yes, but not properly.
I believe that you need to deal with a reputable supplier, Gardiners, GAPs or RoMan, and get top quality membranes from America rather than the Chinese copies.
When I purchased the last membranes from RoMan I also replaced the restriction valve (I use a 3 to 1 ratio unit as my mains TDS is around the 260ppm mark. If your TDS is into the 300's then they recommend a 5 to 1 ratio restrictor. Unfortunately if you are on a water meter you need to find the right compromise).
My advise is to 'bit the bullet' and oder 2 new membranes, the right restrictor valve and start again - buying cheap with regard to RO units is false economy IMO.
Spruce
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Thanks Spruce, I will probs get new membranes, but at the moment tried chris's tip and it seemed to work. I disconnected before the DI and ran the water into a beaker....and it was 350!!!!! after the RO, gradually came down to 50 then 20. Filled up DI with new resin and its back to 000 again, but will see how long for. Will try this tip again and see how long resin lasts. Also second DI was filling up soooooooooooo sloooooooowly, gave it a little twist to the left and filled up immediately. It seemed too tight, if that can be possible or released an air lock.
To be honest, I'm not sure what a restriction valve is, but there is a small black plastic piece on the system with an allen key screw in the top and wires going to it. I'm assuming it could be this, but have no idea what way to turn it to make any difference....lol
Thanks for all the advice/tips.
Fieldsy
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triy to see wots cpming out of menbrans one at at time ,and the other thng is you tds meater not giveing a good reading
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"The chap told me that the fact it's gone down by 300 proves that it's working."
Yes, but not properly.
I believe that you need to deal with a reputable supplier, Gardiners, GAPs or RoMan, and get top quality membranes from America rather than the Chinese copies.
It wasn't a particlarly cheap one,it was in fact one I was recommended by somebody on here.This one:
http://collinswaterproducts.co.uk/product_info.php?cPath=112_126&products_id=169
So the advice is to get new membranes?Fieldsy,sorry if I'm butting into your post but our problem seems very similar.
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Hi
The advert prices a 300gallon per day RO unit with 3 membranes for £131.00. Thats about half the price of a similar one from RoMan etc. 3 decent 100 gallon membranes aren't far short of that.
Your restrictor valve will be on the pipe to waste and will be near your flush valve. When you open the flush valve waste water by-passes the restrictor.
Spruce