[AuRavelling79]

How long since you've replaced the carbon  filter??

[Chris Cottrell]

How much water do you need per day ?

4 vans with tanks ranging from 500- 800lt used  4-5 days a week so a fair bit

[Chris Cottrell]

How long since you've replaced the carbon  filter??

Last changed beginning of Aug

[Smudger]

Personally, I think its time to move onto a 4040

the carbon filter on those is only good for 6000 litres - you need to be changing it every week or at least have another carbon in front of the ro unit

are all the seals and as importantly the housing free from ALL damage and nicks, I have to say at that TDS your leaking tap water into the system.  your welcome to pop over and set it up at mine to see if we can see a problem

Darran

[AuRavelling79]

Okay so your carbon filter is six weeks in. I change mine about that often and if I don't ppm goes up and production slows (and may shorten membrane life).

Further I am only feeding two vans and I would probably go for a higher capacity RO if I was feeding four.

I also have only water rates and no meter.

[Richard Groves]

Some times it's better just to say enough and cut your losses. As others have said it's time for a 4040. Your increased resin costs and lost time and expense would  have paid for it by now.

[Richard Groves]

The pentair or merlin was designed as a low cost compact on demand ro filter for domestic applications. I  started out with a merlin but ditched it within a year. It has a poor rejection rate and  wastes a lot of water. Its been adopted by window cleaners because of its plug and go simplicity and compact size but that's about the only positive  I can see.

[Chris Cottrell]

The pentair or merlin was designed as a low cost compact on demand ro filter for domestic applications. I  started out with a merlin but ditched it within a year. It has a poor rejection rate and  wastes a lot of water. Its been adopted by window cleaners because of its plug and go simplicity and compact size but that's about the only positive  I can see.

I have found it to be a great tool it produced water fast and could cope with filling 4 vans so was a win win for me, the only downside was this recent lack of water quality for which i'm stumped to find the cause of

[Chris Cottrell]

has anyone got any views or experience with the upgraded 750 membranes for the PRF RO, what pressure is ideal for these?

[AuRavelling79]

See my post from earlier on. I bought a set from Gaps Water and installed them 1st week in August.

[Chris Cottrell]

See my post from earlier on. I bought a set from Gaps Water and installed them 1st week in August.

Ahh thanks I did see that and I liked it too, must have a re read of these comments

[AuRavelling79]

Me again...

It's running right now.

Ppm in 231
Ppm out 005
Pressure 57psi
Carbon filter last changed with membranes.

From memory the old ones six/eight weeks in would be about 10ppm.

[AuRavelling79]

Any update Chris? Did you solve it?

[Chris Cottrell]

Not yet I’m going to order some of those 750 membranes and try those there can’t be anything  left to change after that it will essentially be a whole new system

[Chris Cottrell]

Update

I’ve replaced the TLC350 membranes today for the upgraded 750’s and that’s brought the TDS  down to 28ppm before it goes into the resin canister

The old membranes that I installed in May seem ok but do appear to be open on the side not sure if this was the cause or not

[AuRavelling79]

Update

I’ve replaced the TLC350 membranes today for the upgraded 750’s and that’s brought the TDS  down to 28ppm before it goes into the resin canister

The old membranes that I installed in May seem ok but do appear to be open on the side not sure if this was the cause or not

100% the cause. They wouldn't work if split like that. Also 28ppm seems high to me. What's your input?

[Chris Cottrell]

Input TDS is around 500

Output has now settled down to 23ppm

I calculate that to be a 95% rejection rate

[AuRavelling79]

Ah right - that's an exceptionally high input so that might explain it.

[P @ F]

I take it those split membranes where new in when the whole issue started  ?
If so I would be  sending them right back , that’s manufacture defect surely ?

[Chris Cottrell]

I take it those split membranes where new in when the whole issue started  ?
If so I would be  sending them right back , that’s manufacture defect surely ?

I am considering this