[Slash]

I have bought a Pure Freedom van mount with 20" pre filters,my TDS is 230 or there abouts,I use 500 litres daily with a water softener and have the system since July and was wondering when I need to change the two pre filters installed,I notice it takes a little longer to fill the tank as the water preasure is the same on the gauge as I have a booster pump on the system,any ideas!

[NWH]

Most people just change them every so often just to be sure even  if they might not quiet need doing.

[Paul Coleman]

I have bought a Pure Freedom van mount with 20" pre filters,my TDS is 230 or there abouts,I use 500 litres daily with a water softener and have the system since July and was wondering when I need to change the two pre filters installed,I notice it takes a little longer to fill the tank as the water preasure is the same on the gauge as I have a booster pump on the system,any ideas!

I use 20" pre-filters and probably use a little bit less water than you (but not much less).  I change my pre-filters six monthly and that seems to work just fine.  Maybe it can vary depending on what's in the water in different areas but six monthly is fine with my mains TDS of 200 - 250.  TDS isn't the only issue though.  Depends what stuff those impurities consist of.  I would be surprisded if you had a problem though at six monthly intervals.

[Andrew McCann]

Change then now.

It's false economy not to change them every 3 months or so. (Yeah I know I am a supplier) The main purpose of the filters is to protect your RO membrane from chlorine. They have NO tolerance to chlorine which will destroy RO membranes very quickly.

Your drop in production could well be due to the carbon (The 2nd one inline) being exhausted and letting chlorine get at your membrane. It could also be due to a drop in water temperature which will slow down production on any RO system.

I know that this will probably get replies along the lines of..  I have never changed mine etc... well you are the lucky ones. The changeover intervals suggested by good suppliers are NOT a ploy to get more business than they should. They are based on fact to protect your system.

Andrew

[Paul Coleman]

Change then now.

It's false economy not to change them every 3 months or so. (Yeah I know I am a supplier) The main purpose of the filters is to protect your RO membrane from chlorine. They have NO tolerance to chlorine which will destroy RO membranes very quickly.

Your drop in production could well be due to the carbon (The 2nd one inline) being exhausted and letting chlorine get at your membrane. It could also be due to a drop in water temperature which will slow down production on any RO system.

I know that this will probably get replies along the lines of..  I have never changed mine etc... well you are the lucky ones. The changeover intervals suggested by good suppliers are NOT a ploy to get more business than they should. They are based on fact to protect your system.

Andrew

Funnily enough Andrew, it was my supplier that said six months would be OK.  I'm sure they weren't trying to sell me more membranes either  .  Maybe I will increase the frequency a bit to be on the safe side - it's not as if the cost of pre-filters is particularly daunting.

[Andrew McCann]

Personally I wouldn't let it go beyond every 4 months.

I have seen quite a few membranes die an early death because of chlorine ingress and subsequent damage.

20 odd quid (ish) 3 times a year is a small price to pay is money well spent to extend the life of a good 40 inch membrane to it's max. It will also help to keep it operating at peak efficiency throughout it's life with associated minimal resin use and good output.

About the reference to suppliers. I have seen a few posts infering that there is no need to change prefilters at recommended intervals and that it is merely suppliers trying to take money where it is not needed. Every supplier I know.. and I know quite a few do not do this.

Andrew

[Slash]

Personally I wouldn't let it go beyond every 4 months.

I have seen quite a few membranes die an early death because of chlorine ingress and subsequent damage.

20 odd quid (ish) 3 times a year is a small price to pay is money well spent to extend the life of a good 40 inch membrane to it's max. It will also help to keep it operating at peak efficiency throughout it's life with associated minimal resin use and good output.

About the reference to suppliers. I have seen a few posts infering that there is no need to change prefilters at recommended intervals and that it is merely suppliers trying to take money where it is not needed. Every supplier I know.. and I know quite a few do not do this.

Andrew

Andrew
I have spoke with you in the past and am allways greatfull for your input and knowledge,thanks yet again,will order them straight away