Clean It Up
UK Window Cleaning Forum => Window Cleaning Forum => Topic started by: michael robinson on October 21, 2008, 06:35:41 pm
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Hi Guys, ok i want some advice here. i have an ro machine and di vessel. i want to know what on earth is happening, every 2 weeks i have to change my resin in my vessel even though that at present we are only using it 3 days a week so in other words every 6 days i have to keep changing the resin, here is the situation. so from a nice vessel full of new resin i will run ro machine the reading i get from ro machine before it goes through the di vessel is a constant 8 to 10 so after it comes through the di vessel for about the first 3 hours Woopee it has a reading of 0 then it has a reading of 1 and it remains that way until about the last day usually the second week on the wed morning where it will have a reading then of between 2 and 3 then by afternoon reading 4. then i go through the cycle again of changing the resin. Is this normal. the ro machine i got from pure freedom 200gpd and the standard 10inch i think di vessel. the resin i bought from ebay a huge 25lt bag. any suggestions would be appriciated. regards mike
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Hi Michael
What you really need is a proper DI vessel, the one you have is roughly 1 - 2 litres and the amount of water going through it is probably causing tracks and this is allowing water to get through which is not being treated.
Pound to a penny if you get a decent vessel you wont have to change resin for at least 6 months if not 12.
Steve a
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Ok can you tell me what's the best vessel to buy then. regards mike
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Hi Mike
have a look at this - h ttp://www.gapswater.co.uk/acatalog/copy_of_Structural___Park_Vessels.html close up the space after in h ttp
or go onto gardiners website www.gardinerpole systems.com again make it all one word - forum doesn't let you post links apparently.
you want a minimum of 11ltrs capacity so something like the 6"x35" would be fine, bigger the better.
another tip is to disconnect the pipe that goes from the ro membranes into the di at the point where it goes into the di, run off the first 5 ltrs of water and then reconnect without turning the water flow off - the reason for this is the first couple of ltrs of water from an ro when you switch it on are very salty and will eat the resin up extremely quickly
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For the first 5mins of running water through RO the TDS is higher than normal, (test it for yourself). After 5-ish minutes the TDS reduces down to a lower TDS, then it's okay to connect to DI vessel. It's better to run RO into 2 DI vessels (one after the other) rather than one vessel to get more use out of the resin before changing it.
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I would check why your RO is producing a reading of 8 to 10 - perhaps the filters need changing - we have a static RO system in shed and recently had a reading of 8 so changed the filters and all seems ok now
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about why i have a reading of 8 to 10 is our water is hard reading before going through ro is 350 so coming out at 8 to 10 is fantastic.
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what connection do you have to your water supply?
We had a similar problem recently and have finally discovered it was a dodgy saddle valve. When the saddle valve was turned off, it still allowed some water past it, which dripped thrugh the RO system and contaminated the resin in DI very fast.
i had left the pipe from the DI in my storage tank, and unbeknown to me it was dripping, a little, but enough to make the readings go up.
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Don't know if this helps as to how much you can expect from a 10inch DI vessel.
I've been using mine for a year now and on average it produces about 2000 litres of '0' tds water from the '14-20' tds that comes from my 300gpd RO. My tap reading is about 400 most of the time.
I use it up to a reading of '4' tds by which time I've got another 600 litres out of it.
Following that I replace the resin.
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If you haven't run any RO for a couple of days the reading out for a few minutes will be very high. Always disconnect from the resin and run till the TDS is back to normal. Actially it's good prctice to do this every time you run your RO, You will make big savings on resin use. Alan has already made this point.
A reading of 8 from input of 350 is very good. Your water pressure must be good to get this.
Doug Atkinson from this forum supplies good size DI vessels filled with quality virgin resin at very good prices.
Have a look here www.da-services.co.uk/products.htm
Andrew
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I run through R/O and at the mo' it comes out at 10ppm - tho it rises to about 18 after 6 months - it then goes through two 10" vessels.
As said above, always disconnect the resin chambers from the R/O for five minutes and let the water run free when you start up. The ppm is always higher at that point.
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All of the above is good advice. Your fundamental problem though is your DI vessel is far too small. As has been said, get a decent sized pressure vessel 6.9l minimum and it will save you a lot of work.