[MNWC]

Having trouble with my hf5 21 inch membrane.
Im only getting 1 litre a minute with a 70/30 waste ratio although thats enough (just) i have three vans filling up 400 liter tanks daily somedays a top up is needed.
But that would mean the booster pump is running 24/7 !

Has anyone got any facts and figures on optimum flow rates,pressures etc ?

Its a new membrane from grippatank

[Oliver @ GrippaTank]

Good Evening,

The HF5 Membrane can give a maximum output of 150lph based on perfect temperature, flow rate, and pressure.

Ideally you want a minimum of 80-100psi with a minimum incoming flow rate of 314lph per membrane running at temp of 25c.

If you need any further assistance please email support@grippatank.co.uk

[Don Kee]

Is it brand new?

If not, when did you last change your pre-filters?

Whats your water pressure with booster on?

Any blockages?

Good water flow?(not pressure)

If brand new, when you flush (put all water to waste) are you getting lots of water to waste?

Have you plummed it all in right?

[MNWC]

Thanks Grippatank
Ive got a booster pump but its only showing about 50psi after fibredyne filter (new with membrane) when i set the waste to 70%
Ive a tds of 350ish in and 17 coming out at the moment...

[chris turner]

Having trouble with my hf5 21 inch membrane.
Im only getting 1 litre a minute with a 70/30 waste ratio although thats enough (just) i have three vans filling up 400 liter tanks daily somedays a top up is needed.
But that would mean the booster pump is running 24/7 !

Has anyone got any facts and figures on optimum flow rates,pressures etc ?

Its a new membrane from grippatank

What is your mains pressure?
I had a similar problem a few years ago with my hf5 21, my mains pressure was only 20psi, turns out the booster pump required a minimum operating pressure of 40psi so wasn't working efficiently.
I was only getting around 60-70 litres an hour, called out a plumber who replaced the mains valve into the house and the main pressure went up to 45 psi. My RO output immediately shot up to around 120 litres an hour as the pump was now boosting the pressure up to 100psi.
 I now have twin hf5 21 membranes and fill 500 litres in about 2 hours.

[MNWC]

Is it brand new?

If not, when did you last change your pre-filters?  Its a new fibredyne

Whats your water pressure with booster on?  Water comes from a 400 litre break tank due to low pressure

Any blockages?

Good water flow?(not pressure)

If brand new, when you flush (put all water to waste) are you getting lots of water to waste?

Have you plummed it all in right?

[chris turner]

Thanks Grippatank
Ive got a booster pump but its only showing about 50psi after fibredyne filter (new with membrane) when i set the waste to 70%
Ive a tds of 350ish in and 17 coming out at the moment...

Hold on, your setting the waste to 70%??
Try closing the waste valve fully, then opening it up just wee little bit.
My water going in to the RO is 350ppm, I set my waste to about 50/50. Try that.

[MNWC]

I was told to set the waste to pure around 70/30% to suit my tds

[Clever Forum Name]

Way too much waste for that pressure.

80psi would be good for 50/50

You need 60/40

[MNWC]

If its 50/50 then tds is about 30

[martinw]

Are you running this on those plastic taps? If yes change it to gate valve.  Much easier to control  flow and tds.

[MNWC]

Ok let me explain..
Tap pressure is very low (35psi) with a tds of  approx 350 Water is fed into two 200 litre linked water butts.
The two taps on the water butts are connected with hose with and a tee then sucked by my SPE1200SS booster pump to the fibredyne filter then to the HF5 4021 membrane

[chris turner]

Ok let me explain..
Tap pressure is very low (35psi) with a tds of  approx 350 Water is fed into two 200 litre linked water butts.
The two taps on the water butts are connected with hose with and a tee then sucked by my SPE1200SS booster pump to the fibredyne filter then to the HF5 4021 membrane

Surely a booster pump is the wrong type of pump?
A booster pump boosts low pressure, if it's drawing water from tanks it has no pressure to boost. Can't you run the system straight from the main, even 35 psi is better then 0 psi.

[MNWC]

Surely a booster pump is the wrong type of pump?
A booster pump boosts low pressure, if it's drawing water from tanks it has no pressure to boost. Can't you run the system straight from the main, even 35 psi is better then 0 psi.
[/quote]

Chris

Thats what im thinking i'll try it tonight and see what happens

[chris turner]

Surely a booster pump is the wrong type of pump?
A booster pump boosts low pressure, if it's drawing water from tanks it has no pressure to boost. Can't you run the system straight from the main, even 35 psi is better then 0 psi.

Chris

Thats what im thinking i'll try it tonight and see what happens
[/quote]

Even hf5 won't produce a great amount at 50psi.
Someone on here, I think spruce, runs his system straight from the mains at 50psi with no pump and only produces 70litres an hour pure.

Your pump is doing well to get 50psi from nothing, surely it would boost 35psi up to 85psi which would see much better results from the membrane.

[Don Kee]

You're using the wrong pump

A booster pump creates more pressure, its not made to create flow

HF5's need a good flow of water as well as a good pressure (they're not the same thing...)

[Matt.]

I have had similar problems when I got my ro, and tried to fill up at home, direct from the tap, water pressure was so low it barley gave me a trickle, soon cottoned on and now have set jobs I tend to fill up at, good thing is even wen these jobs arnt due am still able to use there taps.

[Spruce]

Surely a booster pump is the wrong type of pump?
A booster pump boosts low pressure, if it's drawing water from tanks it has no pressure to boost. Can't you run the system straight from the main, even 35 psi is better then 0 psi.

Chris

Thats what im thinking i'll try it tonight and see what happens

Even hf5 won't produce a great amount at 50psi.
Someone on here, I think spruce, runs his system straight from the mains at 50psi with no pump and only produces 70litres an hour pure.

Your pump is doing well to get 50psi from nothing, surely it would boost 35psi up to 85psi which would see much better results from the membrane.
[/quote]

Mine does 2lpm or about 120lph Chris which is more than fast enough for us.

My r/o has a rejection rate of 98.5% atm.

I did an experiement the other day. I reduced the flow into my r/o which reduced the pressure from 50psi to 30psi. My new rejection rate was 97.5% at 30 psi. I didn't adjust the waste gate; had I throttled it back slightly I may have been able to improve the rejection rate closer to my normal.

-

[Ian Lancaster]

Ok let me explain..
Tap pressure is very low (35psi) with a tds of  approx 350 Water is fed into two 200 litre linked water butts.
The two taps on the water butts are connected with hose with and a tee then sucked by my SPE1200SS booster pump to the fibredyne filter then to the HF5 4021 membrane

So with this scenario the mains pressure is immaterial - provided there is enough flow to keep your water butts topped up while the pump is running that's all you need.  What diameter pipes are you using from the butts to the pump?  They should be at least 1".  The 15mm mains pipes only deliver a high(ish) volume of water because of the pressure behind it.  Your pump is having to first overcome the resistance of the water coming through a relatively narrow pipe before trying to raise the pressure and deliver a higher volume than is coming in.   To have a pressure of 40psi you need a head of 92.27 feet, your water butts have at best a head of 4 feet

[andyM]

You're using the wrong pump.
You need a Booster Pump, something like this works great with 30psi + mains water pressure and will give you 100 psi at the membrane or less (80 psi) if you wish by tweaking the waste valve:
https://www.machinemart.co.uk/p/cbm240e-1in-multi-stage-230v-booster-pum/
And you won't need to use any break tank just straight off of the tap.