[chris turner]

Just to say on this, I bought new membranes for my Merlin a little over a year ago and my TDS has now risen to 42 from 14 and resin is going off quickly. We use around 1,000 litres a day. It's time to put my hand in my pockets for a 4040 I think.

You've been saying that for ages

I would of thought a decent setup would be more important then forking out on a new ford ranger...

That post is a few months old now. When we moved into our unit I upgraded to a 4040 at the same time. So there!

POW right in the kisser!
Fair one you got me😉

[AuRavelling79]

Hi Granville,
Out of interest, have you any further updates on your PFR performances please.

Yes. So the system is now coming up 5 months old and as you would expect I have not had to change the membranes. They now produce at 14/16 TDS. A few observations.

After about 4 weeks the out put TDS had crept up to about 008 and then over the next week suddenly shot up to about 25 with reduced flow. I had a brief email exchange with Gardiners who suggested I put a sediment filter before the included RO carbon block prefilter and so I put a 10" (you know the real cheap white thing that is less than a fiver a pop) in line between the tap and the R/O.

This now means that as soon as the TDS rises a bit I change the sediment filter and now get about 8 weeks from the carbon block filter instead of 4 or 5. The TDS settled down to 14/16 again.

If I am changing membranes every 12 months I shall be happy; if less than 9 I shall be rather disappointed. But I don't want to be eating resin at more than about 20/25TDS and would definitely change the membranes by 28/30.

If someone reminds me I'll give a report at the end of October which will be 6 months.

[Tosh]

Interesting. Thanks Malc. I'm gonna be looking at putting a pentair in the van shortly.

[Spruce]

Interesting. Thanks Malc. I'm gonna be looking at putting a pentair in the van shortly.

At Malc figures I would put a 4021 in.

16ppm from 300 is 94.7% efficient. I don't thing that's very good tbh.

I haven't done the maths but what he saved in buying the unit will be more than spent on resin to polish those remaining ppm off.

- that's the conclusion my mate around the corner with his Merlin came to.

-

[AuRavelling79]

Interesting. Thanks Malc. I'm gonna be looking at putting a pentair in the van shortly.

At Malc figures I would put a 4021 in.

16ppm from 300 is 94.7% efficient. I don't thing that's very good tbh.

I haven't done the maths but what he saved in buying the unit will be more than spent on resin to polish those remaining ppm off.

- that's the conclusion my mate around the corner with his Merlin came to.

-

That is a fair point. If you have a lot of water to "make" that will become increasingly important as the membranes degrade.  So figure in the cost of the membranes per 1,000's of litres produced. If mine started off at 004 and are now on 016 who knows where they might be at the end of a year?

The carbon block filter isn't cheap at £18.50 plus vat either.

The membranes and you will need two at a time are £67.00 each plus vat.

[Don Kee]

Gold - try a booster pump. You may not need it water pressure-wise but it should bring your TDS down (a mate of mine got similar figures to you with his merlin, but after using a booster he got pure at around 5/6 constantly)

Blackadder - if you're putting R.O into your van then i'm assuming you want pure at a decent rate? I'd go 40/40 rather than 40/21
The price difference is negligible abd once you get into buying membranes i think they're cheaper...

[johnny bravo]

i still use a 300ro, with a purefreedom booster pump,   200 litres in 3 hours.    still a chore to set up for next days water.  always have to be aware of your pure supply.      if you forget its up @ 6  to get 200 litres to get started, then back on again

[ascjim]

Can a booster pump speed up the water making process?

[martinw]

yes

[Don Kee]

i still use a 300ro, with a purefreedom booster pump,   200 litres in 3 hours.    still a chore to set up for next days water.  always have to be aware of your pure supply.      if you forget its up @ 6  to get 200 litres to get started, then back on again

Add another 150 membrane to make your R.O 450gpd

[Spruce]

Interesting. Thanks Malc. I'm gonna be looking at putting a pentair in the van shortly.

At Malc figures I would put a 4021 in.

16ppm from 300 is 94.7% efficient. I don't thing that's very good tbh.

I haven't done the maths but what he saved in buying the unit will be more than spent on resin to polish those remaining ppm off.

- that's the conclusion my mate around the corner with his Merlin came to.

-

That is a fair point. If you have a lot of water to "make" that will become increasingly important as the membranes degrade.  So figure in the cost of the membranes per 1,000's of litres produced. If mine started of at 004 and are now on 016 who knows where they might be at the end of a year?

The carbon block filter isn't cheap at £18.50 plus vat either.

The membranes and you will need two at a time are £67.00 each plus vat.

You saved money on the r/o, but it will cost you in resin. So break even will be in about 2 years - price of 4040 compared to PRF. When membranes are due it will save you money as 2 PRF membranes are much cheaper than 1 x 4040 is.

My fiberdyne prefilter is £28 + VAT but its good for twice the water usage yours is. I might consider adding another 10" prefilter housing and fitting a fiberdyne prefilter into that. A 10" is £12.00 and good for the same amount of water (-200 liters). That would depend if I could remove the Merlin fiberdyne altogether and leave the housing empty.

I couldn't help remembering how you said that it was so easy to install, so this is a big plus factor.

.

[AuRavelling79]

Gold - try a booster pump. You may not need it water pressure-wise but it should bring your TDS down (a mate of mine got similar figures to you with his merlin, but after using a booster he got pure at around 5/6 constantly)

Blackadder - if you're putting R.O into your van then i'm assuming you want pure at a decent rate? I'd go 40/40 rather than 40/21
The price difference is negligible abd once you get into buying membranes i think they're cheaper...

What pressure would a booster pump take it to? And when does it start being too much pressure?

[Don Kee]

Gold - try a booster pump. You may not need it water pressure-wise but it should bring your TDS down (a mate of mine got similar figures to you with his merlin, but after using a booster he got pure at around 5/6 constantly)

Blackadder - if you're putting R.O into your van then i'm assuming you want pure at a decent rate? I'd go 40/40 rather than 40/21
The price difference is negligible abd once you get into buying membranes i think they're cheaper...

What pressure would a booster pump take it to? And when does it start being too much pressure?

Depends on the booster pump you buy...

I know the one that gardiners sells can take you up to around 85psi, but I know the clarkeCmbe booster that alot buy can take you over 100

As a rule of thumb I think most tend to have theirs set at around 80-90psi which is a safe decent figure but if I'm honest I dont know what 'too much' is but I'd imagine it to be a figure of over 100 (spruce may be able to answer that for you, he's alot more knowledgable on R.O's than I am)

Smudger posted a link to a 'cheaper' one a while back that I cant seem to find the link for. I'm sure he said he'd used it for a while now and it worked fine (hopefully he'll post a link if he sees this!)

I used a booster pump (aquatec 8800) on my 450gpd when I had one, taking my pressure from 30-35 psi to 80psi and the difference in TDS and production rate was noticeably better

Again though, I think it comes down to how much water you need and when you'll reap the financial benefits from the initial outlay

[Spruce]

Gold - try a booster pump. You may not need it water pressure-wise but it should bring your TDS down (a mate of mine got similar figures to you with his merlin, but after using a booster he got pure at around 5/6 constantly)

Blackadder - if you're putting R.O into your van then i'm assuming you want pure at a decent rate? I'd go 40/40 rather than 40/21
The price difference is negligible abd once you get into buying membranes i think they're cheaper...

What pressure would a booster pump take it to? And when does it start being too much pressure?

I doubt you will see much noticeable difference as your water pressure is pretty high anyway.

Its the nature of the design of the r/o. GE designed it for undercounter use in American kitchens as a third tap in the sink. If it removed 90% of 'impurities' in the water the average American would use to make coffee, cooking, drinking water, etc then it's done its job perfectly.

As window cleaners we demand the highest water quality for the job we do which is totally different to what its designed for. We also use vast quantities of purified water in comparison to the meager quantities the unit was initially designed to produce. (It also needed to be a compact unit that produced a reasonable flow of water from the faucet when opened, all requirements we find appealing.)

IMHO its just not designed for the job we are asking it to do.

I seemed to remember there was an article promising that the new PRF replacement would have upgraded membranes for better performance, but this doesn't seem to have happened.

Among window cleaners there will always be a market for an r/o of this type as price plays a big part in many  of the decisions made. There are other major suppliers who also sell the PRF as a window cleaning r/o unit.

.

[Tosh]

Just to resurrect this thread.

I bought a Pentair from Gardiners, here are the results so far.

Pentair unit set up on fifth of October producing water at 6 ppm before the resin

23rd October producing 14ppm

23rd November 14ppm.

[Spruce]

Just to resurrect this thread.

I bought a Pentair from Gardiners, here are the results so far.

Pentair unit set up on fifth of October producing water at 6 ppm before the resin

23rd October producing 14ppm

23rd November 14ppm.

Please tell us your tap water tds and have you any idea of your tap water pressure. Cheers.

[Tosh]

Tap water is 300. 55 psi.

[Spruce]

Tap water is 300. 55 psi.

Thanks. Similar rejection rate to Granville's unit but with lower water pressure. That's interesting.

[jk999]

I know a guy that bought a vyair  4040 ,300 plus tds from tap goes through around 1500 litres a day 5 days a week 600 litres Saturday s changed all his filters and membrane 1 St of August and still coming out of same resin at 001

[NWH]

Sediment is the one you want to change regularly if that gets blocked it will fill slower and kill the next one inline,good quality regularly changed pre filters are what gives you a good after RO reading in my experience.