More than a little confused

[Colin blades]

Ian a bag of resin last me about a year and a half.

 

[Neil Williams]

Neil,
With that high a TDS for the input, roughly what proportion of input water is wasted?

I believe it's close to 25% (3:1 ratio) and that's with a booster pump to lift the psi to 65.
Lower pressure would result in higher waste. Higher pressure would reduce the waste but well and truely stuff the filter membranes and the output tds would rise too.

 

[John Bolton]

Thanks Neil,

Bad news if you have a water meter!

 

[Neil Williams]

Not always. There are ways around it!

 

[Trevor Ives]

I ran ours at around 80 psi with an old solution pump from a header tank as our mains pressure struggles to 30 psi most of the time ( we plan ahead when we want a cuppa and book in advance at bathtime!!)
I had an auto rinse on that, I think, flushes every 30 mins for 18 secs.
We wasted around 1/3 with an input tds of around 120 ppm depending on the flow in the river Severn a week before. When we had a very high river it dropped to 70-90.
I ran a membrane for 2 1/2 years after we got the auto rinse. Barely 6 months before due to poor rinsing. The first filter would crud up in around 2 months and look chocolate brown.
The membrane would give around 2 to 5 ppm so the resin lasted well.
And we are on a meter. I used to collect the rinse in a 40 gall barrel and put it through a couple more times until the barrel water got to 3-400 pmm then dump it and start again.
This reduced the wastage to around 15%
I understand there are systems now that have reduced the wastage to better levels.

 

[Neil Legg]

I have started using rain water. TDS is only 19 so resin easily cleans this. Works a treat although it hasnt rained much since August!!!