RO production: What's your mains water pressure? Do You pump? Happy with flow?

[andyseatrout]

Hi,

Having recently been researching the possibility of having to buy a pump in addition to an RO unit, it would be good to build up a picture on others' experiences.

Hopefully this might help others to decide whether or not they need to buy a pump from the outset.

Thanks,

Andy.

[roman]

Great Idea but we must remember different size systems will produce different readings. The fee water flow will be more on larger systems.

[morey]

Mains is 42psi, use ro-man pump to boost this to 70psi. Takes about 3hrs to fill 25ltr drum, which im happy about bearing in mind water temp etc this time of year.

PS TDS in around 300 out 0

[Graham]

Water pressure between 35-40psi with a 3 stage & DI Ro-Man unit and it only takes me about 2 1/2 hrs to fill a 25ltr container :thumbsup:

Well Happy

[Shultz]

Dunno what my mains pressure is, but I have one of the old style ROman pump boxes, normally get between 120-130 psi depending on time of year...

At the moment thats 25ltrs of RO in just over 1hr 30mins on a twin membraned ROMan unit (2x50)

Cheers, Shelton

[designsonline.co.uk]

Water pressure between 35-40psi and it only takes me about 10 mins to fill a 25ltr container - ive got a 720 gpd Merlin Ro Unit, can run off enough water for a complete water change in a few hours if I need to...!

If I put a pump on and ran the unit at full preasure ~ it would do 25 ltrs in under 5 mins
Joe

[Graham]

God thats some unit:)

Do you use it for anything else or do you run an public aquarium :laughing:

Water pressure between 35-40psi and it only takes me about 10 mins to fill a 25ltr container - ive got a 720 gpd Merlin Ro Unit, can run off enough water for a complete water change in a few hours if I need to...!

If I put a pump on and ran the unit at full preasure ~ it would do 25 ltrs in under 5 mins
Joe

[proplus888]

RO-man 4 stage prof 75GPD unit....40psi on mains, using pump to get 70psi, fill 25L container in 2hr 20min.

[Sam_from_Cov]

Hi,

I have a RO-Man 4 Stage Pro. 75GPD running at the average 36PSI and it takes ages to fill a 25L container!

Sam :(

[fire999]

RO man 4 stage. just changed all filters. 40 psi about 6 or more hrs to fill 25 ltr.......


but my input TDS is 75 ppm so there :laugh: :laugh:

To hell with the flow... my tap water is great :D :D

[fire999]

PS....

I tested some bottled water and the TDS is higher here than my tap water :o


Makes you think a bit...:whistling:

[robertreillyNI]

95psi, no pump.

adding another membrane to bring production up.

happy with production rate.

i live on the side of a mountain so the water is pumped up here under huge pressure, i can get nearly 150psi if i turn the water pressure up out in the street but it makes my taps spray and splash when hitting the sink.

[rockaria]

got really low mains pressure...used to take me nearly 12hours to fill a 25 litre container with a 50gpd ro unit. Bought a pump from ro man and now it takes just under 2 hours to fill one.... i leave it running overnight now and it fills my 2ft square mixing tank in 10ish hours (approx 250l) so much much better!!

[gecko]

i thought if the pressure was to low the water quality was worse ?#
anybody

[AlanM]

pressure does affect output quality. If I run with my 35psi main pressure output TDS sits about 14ppm, turn on the pump and wack it up to 100psi then that drops to 2ppm.

Twin 50GPD membranes in series (waste output of membrane one is the source input of the second).



edit: that's the TDS between the membranes and the DI unit, not after DI before anybody says anything. TDS after DI is meaningless in a RO comparison.

[Divejunkie]

RoMan 3 Stage unit...

Was running at 35psi... simply changed my reducer valvle on the mains inlet with an adjustable and I can now wind it all the way up to 8 bar... (120psi!!!)

Running at about 80 psi, flow rate great, excellent flush and Local TDS near 485ppm but comes out at 006 after 3 stage... not worrying about a DI filter at the moment.

Oh.. the adjustable valve cost me about £17

Cheers,

Mark

[nilesh]

What is this adjustable valve and where can I get one from? A picture and/or a link would be good

[AlanM]

pressure reduction valves only help if you have the pressure being it in the first place.

The are used when the main is at a very high pressure, higher than they are supposed to supply and so they drop the pressure.

Sounds like sometimes they drop it too far and so you can up it.

In my case the main is at 35psi so no amount of trickery with valves will help.

[nilesh]

Hi Alan,
Thanks for the response. I'm guessing that the only real solution then is to go for a pump like the one being sold by RO Man. My pressure is about the same as yours, I have a 3 stage with DI 100gpd system at the moment which produces 25 litres in about 4 - 4.5 hours

[Divejunkie]

pressure reduction valves only help if you have the pressure being it in the first place.

The are used when the main is at a very high pressure, higher than they are supposed to supply and so they drop the pressure.

Sounds like sometimes they drop it too far and so you can up it.

In my case the main is at 35psi so no amount of trickery with valves will help.

Absolutely right Alan...

I'm fortunate that my mains pressure needed reducing... that being said after upping the whole house mains pressure I'm much more susceptible to dripping taps etc.

If the mains is below useful pressure for RO, then the only option is a booster pump.

Cheers,

Mark

[AlanM]

Absolutely right Alan...

I'm fortunate that my mains pressure needed reducing... that being said after upping the whole house mains pressure I'm much more susceptible to dripping taps etc.

If the mains is below useful pressure for RO, then the only option is a booster pump.

Cheers,

Mark

Could you not have your new one set at 100psi or thereabouts, tee off for your RO and then put the mains through the old PRV. That way you have two different pressure mains in the property so you have high pressure for RO and lower pressure for everything else. It's a bit of work but may well be worth it.

[roman]

This is all very intresting... But there seem to be some strage pumped systems about running at very low pressure, pumps should be boosting the pressure higher than 40-60 psi as some have indicated..