[Frank pole]

Just checked my RO - The first filter ( the clear plastic one ) fills half way then goes down to about a quater full then goes up to half again! and it carries on like this  - its never done this before - it used to fill right up and stay filled up when mains tap was on - I just checked the quality of the water its producing and its the same as always - 490 in 40ish out! should I just leave it?

[john tomkins]

You are on about the particle filter yes?
Dont see a problem if everything else hasn't changed, although 40tds out seems bit high, unless you got a merlin

[Frank pole]

yes its the particle filter - I was told by pure freedom that the tds was too high so a booster pump was needed but have not bought one yet.

[john tomkins]

Give some details of exact RO you have and water pressure etc, someone may be able to better advise

[Frank pole]

pure freedom 450gpd - water pressure 46psi

[john tomkins]

Doesn't seem that low a water pressure, mine is only 50psi and I got 240tds in and 5 out the ROs before resin, try checking tds out of each membrane individually to see if one isn't seated correctly.

[Andrew McCann]

The smaller Ro's like this one operate at max efficiency at around 70 PSI.

46 PSI is on the low side so a booster pump would help to reduce TDS and increase production. To say the TDS is too high at 490 is wrong though. It is high but a good RO should cope with that and get 97% plus TDS reduction at 70 ish PSI pressure.

One suggestion to get rid of the air in the system is to fully open the flush valve and run it until the air goes though.

Hope this helps

Andrew

[windowwashers]

pure freedom 450gpd - water pressure 46psi

get a 4040

[Frank pole]

OK - Just had a chance to plumb each membrane on its own:

Membrane 1 - tds in 398 tds out 39
Membrane 2 - tds in 397 tds out 40
Membrane 3 - tds in 401 tds out 38

I presume it is a pressure problem!"£$%