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Pure freedom ro

Stu.

New member
Messages
12
Location
Peterborough
Hi guys,

I'm after some advice if I may. As the title suggests I have a Pure Freedom 300 gpd RO. I bought this last November. I was advised at the time that it may be a good idea to buy a replacement pre-filter set, which I did. The guy also advised me that this should be changed approx every 4 months.

My tap TDS readings are about constantly in the 350-380 range. After the RO but before my DI this is normally in the low 30's. Now I must admit from November to now this has always been the case so I have never changed/used my pre-filter kit, until now!!

Over the last week or so my post RO figures have been about 40-45. Now I assumed that I probably ought to change the filters seeing as the guy said "every 4 months" & actually I haven't done so yet. So I change the filters, flush for approx 30 mins, check the reading & its in the high 50's (Post RO pre DI) I've flushed for over 2 hours & it refuses to drop any lower. So now I'm actually getting a worse reading than before changing them.

I phoned Pure Freedom to ask their advice & Frankly the guy ummed & erred a lot & said keep flushing it, & you need to change the pre-filters more regular as these protect the membranes. I explained that with the new filters I'm actually getting a higher reading than the old filters. More umming & erring, suggestion of more flushing & if that doesn't work I may possibly need to change the membranes ££££!! Frankly fairly unhelpful

MY questions are:-

1. are these TDS readings about right?

2. could i have some duff filters?

3. can you even get duff filters?

Also I have a small 10" DI filter. with the TDS readings going into this in the 30-40 mark I'm only really getting 1 full IBC tank (1000L) before the TDS starts creeping up & the resin needs changing again. Is that about right??

Thanks in advance for any help/advice you can offer

Stu

 
Sounds like your membranes could be clogged if you have done the tds creep thing and it doesn't drop down /emoticons/sad.png

 
My tap TDS is about the same and post RO has been creeping up (have a 4040 setup) to similar levels. Speaking to membrane supplier, reckon it's calcium build up due to hard water. Have just taken delivery of new membrane as cheaper in long run than going thru resin at a pace. To prevent happening again, have set up a pump to flush membrane with pure water once IBC is full so that when system not producing, membrane is in pure water so no calcium build up. Recommend flushing before and after every time you produce if not already doing so

 
The sediment filter takes the sediment out of the water so it doesn't clog the membranes. The carbon block filter removes the chlorine from the water that destroys r/o membranes.

My guess is that the carbon block filter has long since ended its useful life and chlorine has now breached and damaged the membranes. However, what you need to do is try to identify if it is just one membrane or all of them not performing.

Take a special note of the way the 3 membrane housings are connected and then strip the unit down so you only have 1 membrane coupled in. Let that run for a period of time and take a reading on the pure side before DI. Do the same with the others. If one is causing an issue with high tds then this is the culprit. If they are all high then there is a pretty good chance chlorine has destroyed the membranes.

In either case you will need to replace the membranes. I would buy 150GPD membranes with the correct restrictor and then resolve to replace your prefilters when they should be replaced.

The 10" Fiberdyne prefilter Gardiner sells will treat 37800 litres of water. If you have a resistor that gives a 3:1 waste to pure ratio then each 1 litre of pure will need 4 litres to process. This means that this filter will give you 9500 litres of pure. (For the 3 of us this filter will last us 2 weeks.) If you are using an ordinary CAG filter then these have a service life of 2500 American Gallons or about 9450 litres. These will be good enough to process 2300 litres of pure.

If you are using 300 liters a day then the Fiberdyne needs to be replaced every 31 working days (approx 6 weeks) and the CAG filters every 7 working days (approx every 10 days).

These figures show you how important it is to replace your prefilters regularly.

The answer to your second question is that the 10" di vessel that comes with the r/o is a waste of time to be honest. You need a bigger di vessel - ie an 11 liter would be better.

Your membranes should be producing pure water to an efficiency of around 97 - 98%. So your membranes should be getting your tap water tds from 380 down to 8. Once the efficiency of your membranes drops to 94%, it is time to replace them. (94% is a tds of 20).

I hope this helps.

 
Last edited by a moderator:
Thanks guys, going to check in the morning as I may have made a big schoolboy error!! After I had been flushing/buggering around with it on & off most of the day I turned the water off only to realise I had barely opened the tap, thus a slow dribble was coming through. Wondering if my errant readings may be due to less head of water than normal pushing through the system. Going to test the theory tomorrow.

Stu

 
Let us know how you get on :thumbsup:

Thanks guys, going to check in the morning as I may have made a big schoolboy error!! After I had been flushing/buggering around with it on & off most of the day I turned the water off only to realise I had barely opened the tap, thus a slow dribble was coming through. Wondering if my errant readings may be due to less head of water than normal pushing through the system. Going to test the theory tomorrow.
Stu
 
I'm getting a lot of calls south of the border with change in ppm from r/o. Can someone tell when you turn your tap on is your water warm as this will make a difference. If so the water molecules may have got less hence all the problems. Our water in Scotland is still cold.

 
My tap water is still cold Doug

I'm getting a lot of calls south of the border with change in ppm from r/o. Can someone tell when you turn your tap on is your water warm as this will make a difference. If so the water molecules may have got less hence all the problems. Our water in Scotland is still cold.
 
I'm getting a lot of calls south of the border with change in ppm from r/o. Can someone tell when you turn your tap on is your water warm as this will make a difference. If so the water molecules may have got less hence all the problems. Our water in Scotland is still cold.
My tap water still cold, no discernible change from normal.

 
The water coming out of our mains tap is 18 degrees C. I've just measured it. We live on Teesside. That is much warmer than it is in the winter. The last check I did was a Christmas time and the water was 9 degrees C. We had a very mild winter last year. I think we only got frost 2 or 3 times over the whole winter period.

The water in van's tank is 21 degrees.

I think our normal winter water temperature is between 3 and 6 degrees C.

 
That's interesting spruce as even though my running tap water seems cold to me it's actually 17 c

 
That's interesting spruce as even though my running tap water seems cold to me it's actually 17 c
We have a hot water cylinder storage tank upstairs in the airing cupboard. An evening bath in the winter uses most of that hot water in it where we use much less for each bath in the summer. (We can usually get 2 baths out of it.) The hot water temperature in the hot water tank remains the same throughout the year as it is controlled by a thermostat on the gas boiler.

I'm sure our experience of differing cold water tap winter to summer temperatures are the same for most people.

 
I'm getting a lot of calls south of the border with change in ppm from r/o. Can someone tell when you turn your tap on is your water warm as this will make a difference. If so the water molecules may have got less hence all the problems. Our water in Scotland is still cold.
Hi Doug

Our tap water tds is 103 this morning which fluctuates between 90 and 115 when I test it from time to time.

I have noticed that my pure from the r/o is at 3ppm at the moment where it is usually 2. I have noticed over the years that the r/o is more efficient in winter than in summer, although the rate of production is much less in winter obviously. My system is unpumped (no booster pump) and our water pressure is around 50psi. I use an HF5 4040 membrane.

 
Hi Spruce,

I'm waiting feedback from the manufacturer on performance and water temp. I do know when it is colder output slows as water molecules are denser.

 
Hi Spruce,
I'm waiting feedback from the manufacturer on performance and water temp. I do know when it is colder output slows as water molecules are denser.
That would be interesting. Warm water has a lower viscosity than cold water, so warm water should pass through the r/o membranes more easily than cold water. But what happens to the dissolved solids in warm water? Do they also change viscosity with the water's temperature thus allowing more 'particles' to pass through the membrane?

 
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