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RO 4040

90 -98% rejection rate?

I am suspicious of the origin of this membrane and would rather put my money into a more expensive membrane with a credible track record.

Lets consider this from their website. If I have tap water of 250ppm and I go with the 2 quoted rejection rates using 12000 liters of pure a month.

98% rejection rate = pure 5ppm - will cost me £9 a month on resin.

90% rejection rate = pure 25ppm - will cost me £44.00 a month on resin

One supplier advised me many years ago that a 94% rejection rate is the time to replace the membrane.

If I'm unfortunate and get a rejection rate of 94% from day 1, resin will cost me £26 a month - £312 a year.

That initial cost saving of the membrane will be offset by increased resin costs within a year. Sorry but that's not good enough. Just my opinion.

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Puts things into perspective when explained in detail, the 90 to 98 percent will that be due to tap pressure?

 
Puts things into perspective when explained in detail, the 90 to 98 percent will that be due to tap pressure?
My HF5 membrane is 4 years old. Our water pressure is 50psi and it produces at a rejection rate of 98%.

I'm sure the manufacturers would have given those figures to Collins. Are these poor figures due to water pressure or are they because of an inconsistent manufacturing process? Do I want to spend £146.00 to find out?

A manufacturer can cover themselves by adding conditions to the performance of the membrane they sell. Some will detail the test conditions where they managed to achieve the best of all worlds, high water production and high membrane efficiency. So they record water temperature, pressure and the compound of the water. They want to show and advertise their product in the best light. 90% is not good for window cleaning.

These specs remind me of the old Merlins, 90% rejection rate out of the box. This was fine for an under kitchen counter water purifier in American kitchens, but not suitable for water processing for window cleaning.

We have the choice of HF4 or HF5 membranes depending on water pressure. What HF are these membranes? They are listed as High Flow. That doesn't give us enough information.

At this price I'm sure Collins will sell lots of these to window cleaners because to me it seems that price sells. We will see the reviews come in time. But I wonder if the complaints will be directed toward the resin not lasting as long as it used to rather than the true culprit.

HID 4040 HIGH FLOW RO MEMBRANE WINDOW CLEANING SYSTEM COMPLETE | eBay

I see they have changed their info on this offer. The membrane has a rejection rate of up to 98%.

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OBTW, this is the first time I've seen window cleaners and or window cleaning included on Collins Water's site. /emoticons/wink.png

As I've stated before, I have no axe to grind with Collins at all.

I just don't believe, until now, that they catered for products for window cleaning. We need products tailored for our industry which sellers like Gardiners, Daqua, Purefreedom, WCW etc do.

The products are a little more expensive from these suppliers, but for good reason.

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Good reading agiain Spruce, plenty food for thought in the long run you only get what you pay for I guess, so far my little 450gpd is doing a good job considering producing plenty enough for me, but I'm always looking forward as my round is growing at a fast rate so maybe this time next year I will need to upgrade 4040.

Another question (terrible at maths) what is my rejection rate tap fluctuates between approx 270 and after RO 007

Thanks in advance.

 
Not sure lot off debate on these and if it's included why not use

Doesn't it reduce the size of contaments therefore making the carbon block filter last little longer ?

 
Not sure lot off debate on these and if it's included why not use

Doesn't it reduce the size of contaments therefore making the carbon block filter last little longer ?

 
Not sure lot off debate on these and if it's included why not useDoesn't it reduce the size of contaments therefore making the carbon block filter last little longer ?
We have only ever used 2 prefilters, a sediment and a carbon block.

Most of the commonly available sediment filters are 5 micron. The carbon block is also a 5 micron one. So what isn't blocked by the sediment filter, particles smaller than 5 micron, will also not be blocked by the carbon block filter. We tried a 1 micron carbon block long life filter and it didn't last the distance as the filter just got blocked up.

The main wfp suppliers sell units with 2 prefilters, 1 sediment and 1 carbon block.

I once did an exercise on what a carbon block filter removes from the water and what a GAC filter removes from the water and it was the identical same minerals. They were just listed in a different order. I have a 20" GAC filter under my desk. Its has a service life of 2500 gallons of water, waste and pure combined.

I once read that a GAC filter is better than a normal carbon block, so by putting it after the cheap carbon block filter they are ensuring that anything missed by the first carbon filter will be caught by the second. Theory says that if both carbon block filters have a service life of 2500 gallons, (USA) or 10000 liters then by adding a second filter they will extend the service life to 5000 gallons.

I've run my 4040 r/o using 2 prefilters, 1 sediment and 1 carbon block for the past 4+ years. I use Fiberdyne carbon block from Gardiners as they have a long service life, 75000 liters. The Fiberdyne could also be used as a sediment filter as well, but as our water if full of sediment on occasion, (I sometimes have to change the sediment filter more often), I chose to leave the sediment filter in place.

I have chosen to use filter bowls that are clear so I can see the state of each filter. On hindsight, I would have just had 1 clear filter bowl as the Fiberdyne filter is always clean, whereas the sediment filter can show red staining within days of replacing it.

The first RoMan type r/o I had had a clear sediment filter housing, a standard carbon block housing and a clear resin housing.

There is a cleaner in Southampton who has a sediment prefilter and a large di vessel filled with acid washed charcoal as his prefilters. He has been doing this for 3 or 4 years now. The di vessel with acid washed charcoal is the first filter and the second is the sediment filter to catch any fine charcoal bits so they don't block the r/o membrane. Last post I read is another cleaner in Norfolk is also headed in that direction. When you have a number of vans on the road and a central filling point, changing 20" carbon block filters every couple of weeks can be a bit tedious. The cleaner in Southampton replaces his acid washed charcoal about once a year - around 400,000 liters (his estimate).

If you are filtering water for drinking, then there are different filters added to make the water taste better, but that doesn't apply in window cleaning applications.

As far as window cleaning is concerned, any contaminates that are missed by the prefilters and r/o membranes are caught by the resin we use to polish the water off.

The carbon block filter is there to remove chlorine from the water as chlorine is the chief destroyer of the materials the membrane is made from. We aren't bothered about taste as we aren't going to drink it, especially after its been through a resin wash.

So IMHO Collins could do away with one of the filter bowls and make the first one clear so you have a visual of the condition of the sediment filter. I have a pressure gauge each side of the prefilters so can also see at a glance the difference between tap water pressure and the pressure on the other side of the prefilters. Once the difference gets to around 10 psi, I just change the sediment filter if the Fiberdyne isn't due for replacement yet.

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We have only ever used 2 prefilters, a sediment and a carbon block.
Most of the commonly available sediment filters are 5 micron. The carbon block is also a 5 micron one. So what isn't blocked by the sediment filter, particles smaller than 5 micron, will also not be blocked by the carbon block filter. We tried a 1 micron carbon block long life filter and it didn't last the distance as the filter just got blocked up.

The main wfp suppliers sell units with 2 prefilters, 1 sediment and 1 carbon block.

I once did an exercise on what a carbon block filter removes from the water and what a GAC filter removes from the water and it was the identical same minerals. They were just listed in a different order. I have a 20" GAC filter under my desk. Its has a service life of 2500 gallons of water, waste and pure combined.

I once read that a GAC filter is better than a normal carbon block, so by putting it after the cheap carbon block filter they are ensuring that anything missed by the first carbon filter will be caught by the second. Theory says that if both carbon block filters have a service life of 2500 gallons, (USA) or 10000 liters then by adding a second filter they will extend the service life to 5000 gallons.

I've run my 4040 r/o using 2 prefilters, 1 sediment and 1 carbon block for the past 4+ years. I use Fiberdyne carbon block from Gardiners as they have a long service life, 75000 liters. The Fiberdyne could also be used as a sediment filter as well, but as our water if full of sediment on occasion, (I sometimes have to change the sediment filter more often), I chose to leave the sediment filter in place.

I have chosen to use filter bowls that are clear so I can see the state of each filter. On hindsight, I would have just had 1 clear filter bowl as the Fiberdyne filter is always clean, whereas the sediment filter can show red staining within days of replacing it.

The first RoMan type r/o I had had a clear sediment filter housing, a standard carbon block housing and a clear resin housing.

There is a cleaner in Southampton who has a sediment prefilter and a large di vessel filled with acid washed charcoal as his prefilters. He has been doing this for 3 or 4 years now. The di vessel with acid washed charcoal is the first filter and the second is the sediment filter to catch any fine charcoal bits so they don't block the r/o membrane. Last post I read is another cleaner in Norfolk is also headed in that direction. When you have a number of vans on the road and a central filling point, changing 20" carbon block filters every couple of weeks can be a bit tedious. The cleaner in Southampton replaces his acid washed charcoal about once a year - around 400,000 liters (his estimate).

If you are filtering water for drinking, then there are different filters added to make the water taste better, but that doesn't apply in window cleaning applications.

As far as window cleaning is concerned, any contaminates that are missed by the prefilters and r/o membranes are caught by the resin we use to polish the water off.

The carbon block filter is there to remove chlorine from the water as chlorine is the chief destroyer of the materials the membrane is made from. We aren't bothered about taste as we aren't going to drink it, especially after its been through a resin wash.

So IMHO Collins could do away with one of the filter bowls and make the first one clear so you have a visual of the condition of the sediment filter. I have a pressure gauge each side of the prefilters so can also see at a glance the difference between tap water pressure and the pressure on the other side of the prefilters. Once the difference gets to around 10 psi, I just change the sediment filter if the Fiberdyne isn't due for replacement yet.

.
Good post

I've just checked the tds now it's run a little and it's 4ppm

One thing I'll be doing is actually fitting a inline tds meter and clear sediment housing

I'm really happy though so far

 
Good postI've just checked the tds now it's run a little and it's 4ppm

One thing I'll be doing is actually fitting a inline tds meter and clear sediment housing

I'm really happy though so far
Having that inline tds meter is a real asset. I played around with the waste gate valve opening and closing it slightly and monitored the pure output until I got the best result. I marked the valve handle which happens to be in the 6 o'clock position. I can close it slightly more to about 1/2 way to the 7 o'clock position in the summer when the water is warmer.

I drilled a 1mm hole through the gate valve to ensure that it could never be closed entirely.

Half my window cleaning life was consumed by insufficient water being produced by my 450GPD for 3 cleaners. I just couldn't believe the difference in production rate between my old r/o and this one. I was in awe tbh and still am.

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