[cockney rebel]

I am moving & where i am going the water pressure is really low..20psi. Can i fill up my tank from the tap first then fit a RO unit in the van and do it that way. If so how can i do it. Thanks for any help.

[Mist A Bit]

you`l need a booster pump before your ro to boost up the pressure. If u fill your tank straight from the tap you`l have to use di only which will be fine for a low tap tds

[Paul Coleman]

I am moving & where i am going the water pressure is really low..20psi. Can i fill up my tank from the tap first then fit a RO unit in the van and do it that way. If so how can i do it. Thanks for any help.

I don't see why not.  I take it you mean tap to static water tank then pump into van RO via hose?  A bit of fiddling about but it sounds quite feasible.
Alternatively there is a (rather expensive) membrane that can work at low pressure but I don't know if 20PSI is too low for it.  It's the
HF5-4040 Ultra Low Pressure Membrane.  If it can be used in your situation it may pay you to investigate that route rather than all the other messing about.

[cockney rebel]

Thank you for your advice.

[D B Services]

You can put the water into a tank first but it wont work in practice.

You need at least 50% of the water to go to waste out of the RO.  E.G. you would only get 250 litres from a 500 litre tank. You need it to got through the RO fist then into the tank. At 20 PSI you will need a booster pump as well.

Dan

[NJWindowCleaning]

Hi I thought it was only the first 10 gallons of water you dont use when you put new membranes in.

As a mate of mine has put the waste to go back through system and he said he hadnt have any problems with his system.

So could you not put the waste to go back into the feeding tank to the ro??

And then you could use a ro in a van.

[SherwoodCleaningSe]

Waste needs to go to waste, you can recycle some of it but if you recycle all of it then the ro membrane won't last too long.  RO's in van setups work by slowly producing the water when not in use, ie overnight and then you have a full tank of pure in the morning.  You can knock water up on the job as well but you need access to a tap and also a drain for the waste to go down.

If you are in a low pressure area then a booster pump is recommended however this membrane might just do the job.

http://www.gapswater.co.uk/acatalog/RO_UltraTec_HF5_SERIES_-_Ultra_Low_Pressure_Membranes.html

Simon