Innocence & Experience

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RO Pressure
« on: June 01, 2018, 08:33:53 pm »
Hi All
Looking for some advice on my RO water Pressure.
This is my 1st attempt at setting one up and my water pressure coming out of the carbon filter and going into the 1st RO membrane was only only 22 so i've fitted an Aquatec booster pump which has increased it but only to 42 when i was expecting anywhere between 60 & 80.
As a result of doing this my TDS before the DI has dropped from 45 down to 21 which is great but again  i expected better!
Can anyone put some light on this for me or do you think thats the best i can expect?
Cheers

p1w1

  • Posts: 3873
Re: RO Pressure
« Reply #1 on: June 01, 2018, 10:26:11 pm »
What type of ro are you using? And what ratio pure to waste is it set at ?

Innocence & Experience

  • Posts: 110
Re: RO Pressure
« Reply #2 on: June 01, 2018, 11:25:52 pm »
Hi
The RO is an Aquati fitted with sediment and carbon filters followed by 3 x 150 gpd membranes, total 450 gpd.
As for the pure to waste ratio, there isnt an adjustable setting>

nathankaye

  • Posts: 5366
Re: RO Pressure
« Reply #3 on: June 02, 2018, 12:12:05 am »
Ideally on these small Ro's you need a psi of 70.

I also have my booster pump fitted after the prefilters and just before the membranes.
https://youtu.be/EpqWaagulfQ

Putting psi to one side for the moment, how long since new have you ran it for? When I first bought my purefreedom RO without the booster, it took a small while for it to start working efficiently and same again when i replaced all the membranes. So  by perhaps running it for some time, before checking your readings might be beneficial.

The booster pumo i use is a cheap ebay one from china, set to 75psi and take my pressure from 30 /40psi to 70psi
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Spruce

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Re: RO Pressure
« Reply #4 on: June 02, 2018, 05:24:45 am »
Hi
The RO is an Aquati fitted with sediment and carbon filters followed by 3 x 150 gpd membranes, total 450 gpd.
As for the pure to waste ratio, there isnt an adjustable setting>

As asked: what is your pure to waste ratio?
Success is 1% inspiration, 98% perspiration and 2% attention to detail!

The older I get, the better I was ;)

Innocence & Experience

  • Posts: 110
Re: RO Pressure
« Reply #5 on: June 02, 2018, 10:40:26 am »
The system has been running for a while now and just doesnt seem to be improving, the pressure is still only 42 with the pump running!
Its an Aquatec 8800 so should be a quality pump. starting to suspect there's an issue with it and will be calling Window Cleaning Warehouse on Monday to see if they can shed any light on it.
I'll measure the product to waste ratio later, what should it be?

andyM

  • Posts: 6100
Re: RO Pressure
« Reply #6 on: June 02, 2018, 10:44:57 am »
Where's your pressure gauge situated?
One of the Plebs

Innocence & Experience

  • Posts: 110
Re: RO Pressure
« Reply #7 on: June 02, 2018, 10:58:10 am »
I've tried the pump before the sediment filter and then the pressure gauge before the water enters the RO Membranes, this gave a pressure of 42.

I then tried the pump after the carbon filter followed by the pressure gauge just before the RO Membranes and again this resulted in a pressure of 42 but this time lots of vibration from the pump outlet pipe causing the gauge needle to bounce all over the place.

Very frustrating!!!!

p1w1

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Re: RO Pressure
« Reply #8 on: June 02, 2018, 10:59:15 am »
are you using a flow restrictor?

andyM

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Re: RO Pressure
« Reply #9 on: June 02, 2018, 11:06:27 am »
I've tried the pump before the sediment filter and then the pressure gauge before the water enters the RO Membranes, this gave a pressure of 42.

I then tried the pump after the carbon filter followed by the pressure gauge just before the RO Membranes and again this resulted in a pressure of 42 but this time lots of vibration from the pump outlet pipe causing the gauge needle to bounce all over the place.

Very frustrating!!!!

Pressure gauge before the membranes sounds correct.
It does sounds as if there is some restriction in your system.
Before writing the pump off I would first check that the inlet hose is free flowing and importantly not kinked all along it's length .
Then check and adjust any flow restrictor valve.
Oh and did you take the wrapping off of the pre- filters before use?
Just a thought!....
 
One of the Plebs

Innocence & Experience

  • Posts: 110
Re: RO Pressure
« Reply #10 on: June 02, 2018, 11:16:15 am »
I have 800 rated flow restrictors on all 3 waste pipes with a flush bypass too.
I've checked the water flow from the source to the system and all is flowing correctly with no restrictor, and yes the wrappers have been removed.
I'm determined to solve the problem but its driving me nuts!! AND WIFEY!!!!!!

Innocence & Experience

  • Posts: 110
Re: RO Pressure
« Reply #11 on: June 02, 2018, 11:36:15 am »
Could it possibly be that my home water pressure is so low, 22 ish, that there just simply isnt enough water to actually boost!!!
I dunno, clutching at straws now!!

p1w1

  • Posts: 3873
Re: RO Pressure
« Reply #12 on: June 02, 2018, 11:38:57 am »
I think those aquatec pumps have a small hex nut that you can turn with an allen key to adjust the pressure(although they should already be set properly), may be worth a try. Personally i'm not a fan of 3 separate restrictors on these 450gpd units  my old one used to have just 1 on the waste pipe after all 3 membranes, when i installed 3 seperate ones the rate of pure water reduced quit a bit so went back to just a single one.

p1w1

  • Posts: 3873
Re: RO Pressure
« Reply #13 on: June 02, 2018, 11:42:22 am »
Could it possibly be that my home water pressure is so low, 22 ish, that there just simply isnt enough water to actually boost!!!
I dunno, clutching at straws now!!
I doubt thats the issue, thats what the booster pump is for, if anything like that is the cause then its more probably your actual water flow. How many litres a min is your mains water flow.
Also it may help if you put a pic up of how you have it set up so people can actually see it.

Innocence & Experience

  • Posts: 110
Re: RO Pressure
« Reply #14 on: June 02, 2018, 01:06:53 pm »
My water is coming out the mains at 4.7 litres per minute, hope that means something to you.

Innocence & Experience

  • Posts: 110
Re: RO Pressure
« Reply #15 on: June 02, 2018, 01:08:48 pm »
i've dismantled all again and Wifey wants me away from it so ill put back together tomorrow and post a pic!

mufcglen

  • Posts: 1507
Re: RO Pressure
« Reply #16 on: June 02, 2018, 01:25:17 pm »
hows your tap pipework connected to your main water feed in the house?
i had one of these self tapping kits and it was useless, once i put a proper t piece feed in the water main pipe the flow and pressure rocketed up from the tap at the front of the house.
4.7 litres a minute sounds like what i had until i put a proper joint in and am  now getting 16-18 litres a minute and pressure went from 25-30 psi to 60-70 psi.

p1w1

  • Posts: 3873
Re: RO Pressure
« Reply #17 on: June 02, 2018, 01:38:06 pm »
My water is coming out the mains at 4.7 litres per minute, hope that means something to you.
thats quite a poor flow really, that will reduce further when showers/washing machine etc is on too. However i dont think that is the main cause of your problem but the flow could be better really. Personally i would only use 1 flow restrictor after all 3 membranes.
This is how i used to have mine set up http://www.ro-man.com/manuals/200300gpdmanual.pdf

Innocence & Experience

  • Posts: 110
Re: RO Pressure
« Reply #18 on: June 02, 2018, 09:27:35 pm »
Hey Hey Hey!!!!!! Sorted.

Removed 2 of the flow restrictors from the waste line, leaving just 1 x 8oo rated and BINGO, 80 Big Fat PSI.

Thankyou so much to everyone who commented, learnt so much about the RO System but probably lots more to learn.

This forum is a massive resource of info, THANKYOU ALL.