[peekeclean]

hi all just been looking at gardiners r/o for around £300 but it says  No specific choice recommendation will be made by our Customer Services Team, so who has one and what do they think of them? iv got a ro-man 450gpd at the moment with around 300ppm going in and around 12/15 coming out(befor D/I) will this do the same job ? i just need a bit quicker to fill my ibc,
and what membrain have you got?
thanks for any advice guys.

[alanwilson]

If you go for the cheaper option (500gpd) then you probably won’t notice any improvement.

You need to go for a commercial membrane to see any noticeable difference such as the hf4 4021

[peekeclean]

yes alan your right if i went for the 500gpd i would only be 50gpd better off which would be nothing. but what sort of pure to wast would i get?

[Don Kee]

Do you have a booster pump on your 450?

[Ian Lancaster]

Hi Joe,
The only real way is to go for a 40-40 if you want quick filling.  We've got one that I bought from RO-Man umpteen years ago - 300ish ppm in and about 6-8 out, but every membrane we've bought has been slightly different in performance.  We also use a Clarke booster pump, really chucks the pure out

Cheers,

Ian

[AuRavelling79]

The PRF-RO Pentair/Merlin RO is a good step up from the 300GPD malarkey but not as fast as a 4040.

Mine gives me 70 litres about of pure per hour at between 008 and 012 at 70 PSI starting at 325/375TDS. After about a year - as long as the pre filter is changed every 6 weeks or so - the TDS rises to about 15 - 18.

It feeds me and Dan amply.

However I am not on a meter and I believe that twice as much water goes down the drain as pure is produced. AFAIK there is no adjustment.

[Spruce]

The PRF-RO Pentair/Merlin RO is a good step up from the 300GPD malarkey but not as fast as a 4040.

Mine gives me 70 litres about of pure per hour at between 008 and 012 at 70 PSI starting at 325/375TDS. After about a year - as long as the pre filter is changed every 6 weeks or so - the TDS rises to about 15 - 18.

It feeds me and Dan amply.

However I am not on a meter and I believe that twice as much water goes down the drain as pure is produced. AFAIK there is no adjustment.

That's right, but you can fit an inline gate valve and close that slightly to reduce the amount going to waste.

[peekeclean]

hi don yes i have a boost pump, but iv now found a problem with my r/o im sending a lot of wast water compared to my pure so been on to ro-man as i think my flow restrictor is had it, so iv order a new one should make a big difference.

thanks ian for you help as always mate.

thanks joe

[AuRavelling79]

The PRF-RO Pentair/Merlin RO is a good step up from the 300GPD malarkey but not as fast as a 4040.

Mine gives me 70 litres about of pure per hour at between 008 and 012 at 70 PSI starting at 325/375TDS. After about a year - as long as the pre filter is changed every 6 weeks or so - the TDS rises to about 15 - 18.

It feeds me and Dan amply.

However I am not on a meter and I believe that twice as much water goes down the drain as pure is produced. AFAIK there is no adjustment.

That's right, but you can fit an inline gate valve and close that slightly to reduce the amount going to waste.

Thanks for that ... what with me being a bear of small brain would you tell me where exactly?

[richard groves]

The PRF-RO Pentair/Merlin RO is a good step up from the 300GPD malarkey but not as fast as a 4040.

Mine gives me 70 litres about of pure per hour at between 008 and 012 at 70 PSI starting at 325/375TDS. After about a year - as long as the pre filter is changed every 6 weeks or so - the TDS rises to about 15 - 18.

It feeds me and Dan amply.

However I am not on a meter and I believe that twice as much water goes down the drain as pure is produced. AFAIK there is no adjustment.

That's right, but you can fit an inline gate valve and close that slightly to reduce the amount going to waste.

Thanks for that ... what with me being a bear of small brain would you tell me where exactly?

You fit an inline gate valve / needle valve on the waste pipe that you tweak to restrict how much goes to waste..........even better still, put a bypass on that valve - basically a T before and after it with a hose bypassing that valve. You put another ball lever tap on that. Once you are happy with the waste ratio you have set you simply open or close the bypass tap to flush or produce pure.

[Alex Gardiner]

hi all just been looking at gardiners r/o for around £300 but it says  No specific choice recommendation will be made by our Customer Services Team, so who has one and what do they think of them? iv got a ro-man 450gpd at the moment with around 300ppm going in and around 12/15 coming out(befor D/I) will this do the same job ? i just need a bit quicker to fill my ibc,
and what membrain have you got?
thanks for any advice guys.

Hi Peekeclean

We do have production and performance guides on the lower description text on the RO-Kit DIY Assembly  page

Here is the overall guide from this page:

How will each RO Membrane Size Perform?

HF5 3012 - 500gpd

    Optimum Input Water Pressure range is 50-100PSI (3.4-7 BAR)
    Average Rejection ratio - 98% (200ppm down to 4ppm with input water at 25°C)
    Recommended waste water ratios - 1:1.5 under 100ppm, 1:2 100-250ppm, 1:3 250-400ppm
    Nominal 500gpd rating - will produce from 700-1250 litres per 24 hour day

HF4-4021

    Optimum Input Water Pressure range is 80-105PSI (5.3-7 BAR)
    Average Rejection ratio - 98% (200ppm down to 4ppm with input water at 100psi and 25°C input water temperature)
    Recommended waste water ratios - 1:1 under 100ppm, 1:2 100-250ppm, 1:3 250-400ppm
    Suitable for standard water input temperatures +10°C
    Nominal 1,000gpd rating - Real world will produce from 1400-2500 litres per 24 hour day

HF5-4021

    Optimum Input Water Pressure range is 50-100PSI (3.4-7 BAR)
    Average Rejection ratio - 97% (200ppm down to 6ppm with input water at 100psi and 25°C input water temperature)
    Recommended waste water ratios - 1:1.5 under 100ppm, 1:2 100-250ppm, 1:3 250-400ppm
    Nominal 1,200gpd rating - Real world will produce from 1400-2700 litres per 24 hour day

HF4-4040

    Optimum input pressure range 80-105psi (5.3-7 BAR)
    Average Rejection ratio - 98% (200ppm down to 4ppm with input water at 100psi and 25°C input water temperature)
    Recommended waste water ratios - 1:1 under 100ppm, 1:2 100-250ppm, 1:3 250-400ppm
    Suitable for standard water input temperatures +10°C
    Nominal 2,500gpd rating - Real world will produce from 2000-4500 litres per 24 hour day

HF5-4040

    Optimum Input Water Pressure range is 50-100PSI (3.4-7 BAR)
    Average Rejection ratio - 97% (200ppm down to 6ppm with input water at 100psi and 25°C input water temperature)
    Recommended waste water ratios - 1:1.5 under 100ppm, 1:2 100-250ppm, 1:3 250-400ppm
    Nominal 3,000gpd rating - Real world will produce from 2000-5000 litres per 24 hour day

[Spruce]

The PRF-RO Pentair/Merlin RO is a good step up from the 300GPD malarkey but not as fast as a 4040.

Mine gives me 70 litres about of pure per hour at between 008 and 012 at 70 PSI starting at 325/375TDS. After about a year - as long as the pre filter is changed every 6 weeks or so - the TDS rises to about 15 - 18.

It feeds me and Dan amply.

However I am not on a meter and I believe that twice as much water goes down the drain as pure is produced. AFAIK there is no adjustment.

That's right, but you can fit an inline gate valve and close that slightly to reduce the amount going to waste.

Thanks for that ... what with me being a bear of small brain would you tell me where exactly?

On Alex's video about assembling the PRF I see he refers to the waste being 3/8" black push in pipe which pushes into the unit's head and the other goes to the drain at 7.30 minutes.

https://www.youtube.com/watch?time_continue=695&v=s_yoMZv2Ycw

I would use a brass gate valve as its easier to set more accurately than a ball valve is IMO.

https://www.ebay.co.uk/itm/BRASS-GATE-VALVE-BSPT-SIZES-FROM-1-4-TO-4-RATED-TO-PN20/111513070867?var=410505788782&hash=item19f6b26d13:m:mZIcaXBBfUqQJysHCGntEyw

2 x
http://gardinerpolesystems.co.uk/all-products/pump-hose/hose-fittings-adapters/john-guest-fittings/3-8-fittings/john-guest-3-8-push-in-fitting-to-3-8-male-screw-thread.html

I would then cut the hose somewhere near the outlet of the waste from the r/o and insert this gate valve.

According to Alex's spec sheet the r/o will run at about a 3 waste to 1 pure ratio. The older Merlin runs at a 5 to 1.
So what you are doing is restricting or throttling the flow to waste which will increase the pressure on the membranes. You will never completely close this valve.
Your pressure is pretty good and your water has a high tds, so I would be inclined to let 'sleeping dogs lie' in your case.

Alex talks about an average rejection rate - 93% @ 80psi (5.5 bar) with a PRF.  My reasoning is that a 4021 will produce similar amounts of water at a rejection rate of 96 to 98%.

Lets say someones water is 300ppm, their monthly pure  water usage is 5000l and their r/o's rejection rate is 93%, they will use
£15.27 worth of polishing off resin a month according to Alex's resin calculator.

If I put my 4040 into the same senario at a current rejection rate of 98% after 5 years, I would use £4.36 worth of resin.

My water pressure is 50psi so if I purchased a PRF then I would need to also purchase a booster pump. I'm not sure in my case that this is a viable purchase from my own experience. Over 5 years the additional resin would cost me £660.00. Yes, the r/o is cheaper but if I add a booster pump then it isn't.

At 50 psi I doubt that throttling back the waste would do that much to improve the rejection rate. It would only reduce my water bill if I was on a meter.
My mates Merlin produced a rejection rate of 90% at 50psi water pressure when it was new. Its worse than that now.

My opinion though.

What the PRF does save on is the confusing (to some) process of having to instal a solenoid and float valve to switch the r/o off when the tank is full. With the PRF a simple ball valve in the tank will suffice.

.