[groundhog]

I just measured the Lpm from the supply tap, and it is coming out of the tap at nearly 25ltrs per minute. I also borrowed a pressure meter from a friend and it shows the pressure coming out of the supply tap at around 75psi. So it looks like the pressure gauge on my RO is well out with a reading of just 45psi!! 

[groundhog]

Do water pressures vary at different times of the day? I measured my Lpm yesterday and it was over 25ltrs per minute with a psi of over 70, just tested again this morning and the psi has dropped to 40, and the Lpm has dropped to 17?
I need to order a new membrane, should I go for HF4 or HF5? Or should I give up on the 950ro and get a Merlin? 

[Mick Kent]

Simple.
Booster pump and a hf4 membrane.
2x 20inch filters and your away. Will give you below 007ppm from day 1 costing you a sack or 2 of resin a year deprnding how much water you make.

[Smurf]

Merlin is one of the worst ro's you could get so no stay clear of them.
What happened to the hf4 you took out of your 2021 ro?

If it was me before I got a new membrane I would get a boster pump for it then see if it makes any difference as by the sounds of it you will be needing a boster pump  anyway.

Do water pressures vary at different times of the day? I measured my Lpm yesterday and it was over 25ltrs per minute with a psi of over 70, just tested again this morning and the psi has dropped to 40, and the Lpm has dropped to 17?
I need to order a new membrane, should I go for HF4 or HF5? Or should I give up on the 950ro and get a Merlin? 

[martinw]

Simple.
Booster pump and a hf4 membrane.
2x 20inch filters and your away. Will give you below 007ppm from day 1 costing you a sack or 2 of resin a year deprnding how much water you make.

+1


your mains pressure and lpm will vary depending on demand at a time.
 you should usually have around 10-15 psi drop from mains pressure vs ro guage after prefilters. any bigger difference  means usually prefilters need changing- i know its a subjective matter...
do not close the waste valve fully when the mains is running - recipe for issues. 
stay away from merlin.

if you have booster pump try that first. compare pricing 2021 vs 4040. only few quid difference. 

[groundhog]

I hope I have done the right thing, but have purchased a HF5 membrane.. should arrive tomorrow, just hope it lasts longer than the last one!! I'm going to soundproof my shed so that I can use the pump, as I haven't been able to use it as it is far too noisey!!
Thanks for all your help!! 

[Frankybadboy]

i run my low pressure membrane at 40 psi and get 18+ out of it

[groundhog]

i run my low pressure membrane at 40 psi and get 18+ out of it

18+ what? Please explain.. Thanks 

[Frankybadboy]

Sorry I get 18months + out of my membranes

[Mike55]

On the subject of booster pumps - can anyone recommend one suitable to use for a 40/40?

Also, do you run the pump after prefilters (ie directly to membrane) or before the prefilters?

Cheers, Mike

[groundhog]

Sorry I get 18months + out of my membranes

Oh I see, thanks! I just looked out the receipt for the last membrane, and found that it actually only lasted for just over 4 months! The membrane on my old ROman system lasted for 8 years!! and I only got through one bag of resin in all that time, I hardly ever back flushed either!

[Mick Kent]

Sounds like you have blown the membrane up. Did you run on full without any or next to no waste water by accident?? I did this and totally destroyed a membrane the first week i got it.?

[CleanClear]

On the subject of booster pumps - can anyone recommend one suitable to use for a 40/40?

Also, do you run the pump after prefilters (ie directly to membrane) or before the prefilters?

Cheers, Mike

A lot of people here recommend and run the Clarkes CBFM pumps. However i've run this for the past four years and not had a problem..........................
https://www.machinemart.co.uk/shop/product/details/051012200

Its half the price. I have the pump before the pre filters.

[groundhog]

Sounds like you have blown the membrane up. Did you run on full without any or next to no waste water by accident?? I did this and totally destroyed a membrane the first week i got it.?

I did in the end, but the pure production was getting so ridiculously slow that I had to turn the waste water almost completely off to get any pure at all. I thought that this would be ok as my water pressure is quite low anyway?

[Mike55]

On the subject of booster pumps - can anyone recommend one suitable to use for a 40/40?

Also, do you run the pump after prefilters (ie directly to membrane) or before the prefilters?

Cheers, Mike

A lot of people here recommend and run the Clarkes CBFM pumps. However i've run this for the past four years and not had a problem..........................
https://www.machinemart.co.uk/shop/product/details/051012200

Its half the price. I have the pump before the pre filters.

Thanks Bud.  Do you know what fittings I need to connect standard size hose to the pump and from the pump to the prefilters?

Can order the lot at the same time then.

Cheers, Mike

[CleanClear]

Sorry I get 18months + out of my membranes

Oh I see, thanks! I just looked out the receipt for the last membrane, and found that it actually only lasted for just over 4 months! The membrane on my old ROman system lasted for 8 years!! and I only got through one bag of resin in all that time, I hardly ever back flushed either!

I'm not being pedantic but !!! Things can get confusing in these threads................back flushed ? As far as i'm aware "back flushing" is something you do when you have an extra salt filter on for extremley hard water. "flushing" is something you do over and above the RO's usual operation wherby it does flush all the waste away. So "flushing" is just an aid to what it alreay does when it produces water. "back flushing" is totally different?

[CleanClear]

On the subject of booster pumps - can anyone recommend one suitable to use for a 40/40?

Also, do you run the pump after prefilters (ie directly to membrane) or before the prefilters?

Cheers, Mike

A lot of people here recommend and run the Clarkes CBFM pumps. However i've run this for the past four years and not had a problem..........................
https://www.machinemart.co.uk/shop/product/details/051012200

Its half the price. I have the pump before the pre filters.

Thanks Bud.  Do you know what fittings I need to connect standard size hose to the pump and from the pump to the prefilters?

Can order the lot at the same time then.

Cheers, Mike

I'll take some pics and get back to you tomorrow.

[Mike55]

On the subject of booster pumps - can anyone recommend one suitable to use for a 40/40?

Also, do you run the pump after prefilters (ie directly to membrane) or before the prefilters?

Cheers, Mike

A lot of people here recommend and run the Clarkes CBFM pumps. However i've run this for the past four years and not had a problem..........................
https://www.machinemart.co.uk/shop/product/details/051012200

Its half the price. I have the pump before the pre filters.

Thanks Bud.  Do you know what fittings I need to connect standard size hose to the pump and from the pump to the prefilters?

Can order the lot at the same time then.

Cheers, Mike

I'll take some pics and get back to you tomorrow.

Thanks I appreciate that

[Spruce]

On the subject of booster pumps - can anyone recommend one suitable to use for a 40/40?

Also, do you run the pump after prefilters (ie directly to membrane) or before the prefilters?

Cheers, Mike

A lot of people here recommend and run the Clarkes CBFM pumps. However i've run this for the past four years and not had a problem..........................
https://www.machinemart.co.uk/shop/product/details/051012200

Its half the price. I have the pump before the pre filters.

Thanks Bud.  Do you know what fittings I need to connect standard size hose to the pump and from the pump to the prefilters?

Can order the lot at the same time then.

Cheers, Mike

http://www.cleanitup.co.uk/smf/index.php?topic=114348.0