Hi,
My RO just started eating resin for breakfast, dinner and tea. I have a large pure freedom RO system with big booster pump.
Replaced the pre filters and it’s still doing it.
Checked TDS from membrane and it’s 37 which is a little high but still doesn’t explain why it’s eating resin (once a week).
Another thing I noticed was that when changing the resin there is hardly any water in the vessel, the old resin looks quite dry, even though it’s shot. Any one got any idea what might be the prob?.
Thanks
Firstly, you don't mention what size di vessel you have.
You also need to tell us what your tap water tds is. Whatever it is, 37ppm from the membrane isn't good. The higher this figure, the faster you will chew through resin polishing that off.
Changing prefilters won't make any difference to your high pure output. Prefilters are only there to protect your membrane.
Take some of the spent resin from your di vessel, put it into a container and add a little of your 37ppm 'pure' water to it. If it takes the ppm of the pure down to zero, then there is something wrong with the di vessel.
But I would focus on the membrane. IMHO (not shared by everyone), you need to change prefilters according to the manufacturers recommendations. So if they say your carbon block filter should be replaced every 10,000 litres, then that's what I do. (This figure includes waste and pure.)
Your carbon filter removes chlorine from your tap water. Chlorine destroys membranes. None of us know how much chlorine is in our tap water at any particular time. Sticking to the mfg's guidelines has meant my membrane is now over 10 years old and still performing at 97% efficiency. Some argue that had I not replaced my prefilters so often, I would have saved more money, even if I had to replace my membrane say every 5 years. It's all down to 'economies of scale.'
In my case, Northumbrian water has been our only source of supply ever since I started wfp. Initially, I purchased a used r/o which was a year old. It was also used in our area from the same water source. That cleaner never changed the prefilters in the year he had it. Those membranes had to be replaced. I then started to replace prefilters every 3 months, and the next set of membranes lasted 6 years. So I know we can't just change our prefilters once a year.
I use 20" Fiberdyne prefilters that the mfg says are good for 75,700 litres of water. I have my r/o on a water meter and change the prefilters at 77k which is approx every 3 to 4 months. If the chlorine content is much lower than the chlorine content the carbon block is tested against, then in theory my c/b filter should last longer. But, as I said, I have no idea how much chlorine is in my tap water at any given time, so my only option is using the mfg recommendations.