[slap bash]

You will only need to pressurize your RO  not the  prefilters so the booster pump goes between the vessels and R O . The filter are just filter and not membranes of thicker material which need pressure to force the water through. 

[Dave Willis]

So what happens to the prefilters if you have really high mains pressure?  Makes no difference surely.

[nathankaye]

So what happens to the prefilters if you have really high mains pressure?  Makes no difference surely.

Dont think anybody has really high tap pressure

[Dave Willis]

I've heard from an expert on these matters. There's no back pressure from prefilters and barely any drop in pressure. So basically it doesn't matter much where the booster pump is. 

No advantage before or after, whatever is easiest for you.

[slap bash]

You can do as you like because your name is Dave Willis and you are contradictory by nature.

[robert mitchell]

I have had mine set up both ways ....it makes no practical difference .

my old house had 70 psi from the outside tap , had to fit a restrictor on the shower because the head wouldnt stay in the holder so some houses do have high pressure .

my new place has 21psi !

[Spruce]

Thanks guys. My tds reading before di vessel is around 20 so not pure enough for my liking.

Just checked ibc tank and its 36 hours now and done 900 litres(as turned off over night now) so not too bad.

Will definitely look into getting a bigger di and a pump.

I also have an internal pump which sits at the bottom of the tank which you plug in. Fills up a barrel really quickly but haven't tested how low the tank will get before it starts sucking up air as I know this can happen.

How do other people get on with drawing the water out? Do you always need to have a certain amount left in the ibc?

You won't be able to suck all the water out of your IBC tank. We have an external pump with a foot-valve. It starts to suck air when the water level gets down to about 150mm from the bottom.

As far as your r/o is concerned, what it the ratio of your pure to waste? Ours had an inline restrictor which was about 3 waste to 1 pure. You might find if you had an adjustable tap you could reduce your waste to say 2 to 1 and see if that make any difference with efficiency and speed of production.

You might also try to isolate a faulty membrane by disconnecting the other 2 and running them individually testing their pure output results. 

-

[Smurf]

If your new 450 gpm ro output is 20 ppm then something don't sound right to me.
Did you follow the instructions properly as new ro's need to be back flushed through before use?
What is your tap water tds?


To diagnose any issues with the ro production rate you would also need to find out what the tap water flow rate is and bar pressure going into it first then go from there.

Regards di resin how long it lasts as mentioned already are you aware of what's called TDS creep? If not do a search on youtube that will explain this.