[chez]

Hey guys.
Have water pressure of 65 psi which is quite good, but my ro which was replaced back in August 2012 seems to be failing as the tds is creeping up. Tap tds is 240 but comes out of the ro at 20 should be 12 @ 5%. The membrane is HF5 40". I flush once a week for 2/3 hours. Change prefilter every 3 months.
Does anyone know if this type of membrane has to have both carbon and sediment, or is it ok with just the sediment or just the carbon? As my setup is only one prefilter 
( going to swap over to the new ones advertised on the Gardeners website which does both )  I have flushed and flushed but cannot get it down to the 5% mark. Really disappointed that it seems to be failing already 
Any advice from the boffs much appreciated!
Cheers all
Chez
 

[Lee GLS]

If you only have 1 per filter now, that is probably why your membrane has failed. What per filter are you currently using.

You are right about the new one on gardiners website, it does both, and you would be best to go for the HF5 membrane with that water pressure.

My 4040 is nearly 3 years old and in brings the tds down to 10 from 400

[chez]

Hey Lee.
Cheers for your reply. Your system is working really good! From 400 down to 10 is brill.
Got the prefilters and ro from daqua, the prefilter is 10" carbon block 5 micron/sediment from the same supplier. I used the carbon for a while then 3 months later changed to the sediment as they came in a double pack, 2 carbon, 2 sediment. Perhaps that is the mistake? What's your water pressure? Quick question, why would the HF 5 be better?
Cheers

[Lee GLS]

If you have bee running without the carbon filter, then the chlorine on the water has killed the membrane.

The HF4 is for high pressure, the HF5 is much more suitable for home use unless you have a booster pump.

My water pressure is roughly 80psi, but I run a booster pump which makes the RO run more efficiently.

Definitely get the new prefilter from gardiners, and a new RO, and continue flushing as you were, and it should last you many years.

[andyM]

I would agree with Lee that Chlorine has affected the membrane because of not using the carbon block filter.
If I was you I would get a carbon block filter in there as soon as possible and live with the 20ppm TDS output until it creeps up to a high level where you will be going through a lot of resin.
That way at least you can get a bit more use out of the membrane before changing it.

[chez]

Cheers guys.
It's weird cos it is a Brodex system and came with only one prefilter which was a sediment. The first membrane (not sure what it was) lasted 2 years.
But I will definately when this lot of resin has gone replace the ro with a HF5, and use the new prefilters from Gardeners. You live and you learn!

[robert mitchell]

i think you will find that the original brodex filter was a carbon block filter .
The carbon block filters usually filter to 5 microns sediment as well but you ran it for a while with just a sediment filter (no carbon) hence as said above the chlorine has damaged your membrane .
If you had run just a carbon block filter your membrane would have been fine , however the carbon block filter would not last as long without a sediment filter first.

The new filters from gardeners seem the ideal solution.

[chez]

 
[/quote]

My HF5 is still OK after 2 years (as it should be).  I use a 20" sediment and a 20" carbon pre filters (in that order though it may be possible to reverse them).  The set up takes it down from 200 to about 002 at first but it's slowly crept up to about 009/010.  Not a problem as I have resin after it.  My water pressure varies between 35 and 40 PSI.  Production is fairly low but more than enough for me.  About 40-50 litres per hour of pure (depends on temperature).  I change the pre filters after about 4 or 5 months and flush for about 15 minutes once or twice a week.  If you have a problem, it's probably about a pre filter missing.
[/quote]

Hey Paul.
As I have said the system only came with one prefilter and the fist 2 years was trouble free. But then thinking about it I didn't use that much water for the first 6 months or so as I gradually swapped the customers over to wfp. So the water usage has crept up more and more hence the r/o membrane not lasting as long the next 2 years. With only one prefilter (10" at that) and not enough room on the machine to fit a second, will definitely have to swap to the new technology in the new filters advertised on Gardeners with one filter coping with sediment and carbon.
Cheers

[robert mitchell]

I think the problem with carbon block only is that it will block with sediment before it stops removing chlorine which is wasteful.

if you have a sediment filter first both filters will last much longer.

If the new ones gardiner are selling do what they say i think they are definately the way to go.

[Richard Shepherd]

Chez, If you are going to buy a system from Gardiners, give me a bell. I have a brand new one unused sat in my garage you can have at discounted price.

[chez]

Chez, If you are going to buy a system from Gardiners, give me a bell. I have a brand new one unused sat in my garage you can have at discounted price.

Hey Richard,
No I'm happy with the system thanks , not looking to buy for a long time yet, just got to get the filters sorted
Cheers