Mark
I have twins and really i never saw the massive benefit until i added a booster pump. If your pressure is low you will probably be only getting 20% ish pure water. 80% waste. Since adding the booster pump i think i'm getting nearer 50-50 and my produxtion has gone up to about 300 - 400 litres an hour. It runs the system so much more efficiently. So as for your quetion of where to set it will be down to your water pressure
If you take the waste feed of 1 then stick it straight into 2 you will only need the tap set out of the numbers 2's waste.
interested in this post, maybe I'm wrong but is that the correct way to set up twin ro's, wont the second one get knackered more quickly with a higher cocentrate of waste going through it ?
CM I'm just running a single hf5 at the moment, from your experience then if I was just to do one upgrade which do you think would be better, a second ro or a booster pump?, my psi is about 50 and mains tds of about 260 ppm
thanks, simon
We haven't a 40/40 but this is interesting. When we got our 300gpd, 3 membrane R/O unit, all three membranes were linked together in parallel with the restrictor on the waste outlet 'serving' all 3.
I would suggest that you could couple your 2 40/40's together in this way so they are 'balanced' and served by the one adjustable waste tap.
I have seen an R/O supplier who linked the membranes in series, so the waste from the first becomes the input for the second etc. This is supposed to reduce water consumption. I did ask the question regarding membrane longevity when linked this way, but never got a definitive answer. The stress was put on the water savings for those on a water meter which would easily negate the costs of having to replace the membranes sooner, if this was infact the case at all.
I don't know whether the same is strickly true for a more expensive 40/40 membranes though.
Spruce