Hi all,

Please excuse my apparent ignorance. I am not, nor ever will be a professional plumber of any kind. That said, I know my arse from my elbow with mechanics and I'm neither stupid or blind, so this should be relatively simple, I hope


I have a twin RO, (Reverse Osmosis), system - 2 pre-filters, (sediment & carbon), plus 2 40" RO membranes. My water pressure is pretty bad where I live, (top of a relatively small hill tbh, but my water company is bad and allow me 3 cup fulls a minute ).

From the mains outlet, I get 2 bar on a good day. The membranes can receive up to 10 bar, so once the water actually gets to them, it's down to about 1 - 1.5 bar. Water production is, to say the least, pathetic. Takes roughly 10 hours to produce 1000 lts of purified water.

I have looked at small booster pump setups here in the UK, but like EVERYTHING else here, they are WAY over priced, especially for their spec. Just to give you an example, a Draper unit, with a 24lt reciever and 51 LPM self priming pump, with pressure switch, pressure gauge and 3 pin plug, (whoop whoop), comes in at 264 or $428, from a well known supplier here.

I've had a look at e b ay, (having checked the diagrams of these pre-made booster setups), and I have come to the following conclusion as to the parts I would need to make my own, (add/delete/correct as you see fit):


Lowara 60lt, 10 bar receiver - 10 (e b ay - used but excellent condition)

Calpeda NM 2 80 lpm centrifugal pump - 1 (e b ay - new but old stock 242 new in the UK)

Pressure switch - 20 - 3 phase (seller says it's stronger than the "normal" 2 phase here in the UK, I just need to use 2 terminals instead of all 3) - right or wrong?

Pressure gauge - 15 - 12 bar, glycerine filled

Steel hose, (from pump to receiver) - 25 approx

Brass manifold - I've seen both 3 and 5 way manifolds fitted to some of the setups. The Calpeda, as far as I can make out, has only an inlet and an outlet, (correct me if I'm wrong). Would I need a connection for each of these:
in (water)
out (water)
pressure switch
pressure gauge

Making 4 in total, so a 5 way manifold and cap the last, unused one, or have I got the config wrong and if so, please correct me here.

So far, for the sum total of about 90 or $146, I would have a stronger, bigger capacity unit than I could buy for more than twice the price in the UK. Please tell me if I have made any glaring mistakes in this proposed build and list any omissions that might have also been made.

I'm hoping that British engineering principles aren't that different from those practised in the USA and that you guys are able to steer me in the right direction.

I look forward to your replies.

Regards, onetruecharlatan.