[George Gardner]

So as stated above,
New bottom 3 filters
New membrane
New DI

Starts off well 001, thought that will drop to 000 so let it start filling up the 1000l tank.

Come down the next day and the tank water is 9!! Pick myself off the floor and run it through the system for a bit to see what the tds reading is coming out at the DI and after 15 mins that's 12 (hit floor again)

New filters, membrane etc to the tune of 140 quid!

Does anyone have any idea why new filters and membrane would give a tds reading of 12??

[Tom White]

I suspect what has happened is that you've connected everything up with brand new RO membranes and started producing pure water.  But there's some kind of 'stuff' on brand new membranes which needs to be washed away, but since you've had this high TDS water going through your DI chamber, your resin has purified it and quickly exhausted itself; hence the later high TDS reading.

Disconnect the tube going into the DI and tell us what the reading that comes straight out of each RO membrane is.

I suspect all you need to do - if your TDS readings after RO are fine - is reconnect it to your DI chamber and change the resin.

If this is the case, in the future when you replace your RO membranes, just run it for a few hours before connecting it to your DI; just let all the water go down the drain for a while.

[George Gardner]

Hi. Funny one but I have some findings -

Went from the DI vessel chamber lying down (yes in hindsight not a really clever move) to standing up right and it's now 6! So that halved it.

Should the water coming from waste be higher than water at source?

Tosh - thanks for you reply. I have made 1000l so I'm fairly sure on a 300gpd system that's long enough to "flush it".

Pre DI the water is at 9, after only 6.

So actually I've just realised the problem is possibly the DI as it should reduce it more than "3"!

I'll investigate and get back!

[Don Kee]

Its going to sound silly, but give your D.I a big old shake
Sometimes the water will create 'channels' in your resin, and the water will use this route to the outlet
Giving it a shake up will get rid if them


What size is the D.I?
When you fitted (bad english sorry!) the membranes and then ran it for a while, did you disconnect the inlet to the vessel?
Keep the vessel upright
Is it fresh resin?(i'm assuming it is...)
Is your holding tank clean?


Resin should bring your tds to 000 no matter what the tds of the water you put in...
Higher tds just spends it quicker

Few things to think about while trying sort it...

[George Gardner]

Hi don - thanks for the reply.

I've done just that - a big 'ol shake I'll see what happens!

I'm going to change the resin. My belief now, having spent most of the day with this, is that not leaving the 3 "bottom filters" (I always laugh) long enough to flush through before connecting the DI to it. In doing so I've somehow "knackered" my resin.

Like you say resin should produce 000 readings and it only reduces the water tDs reading by 003. So it's the resin!

A bit like what tosh said - message to everyone - flush through the filters before connecting to membrane, AND even then flush through again before connecting to DI.

In short...............read and follow the bloody instructions George!

[Frankybadboy]

make sure all your rubber seals are fitted


we don't want to leave them out do we don key

[Dave Willis]

Don't suppose you've left the flush valve open?

[Don Kee]

make sure all your rubber seals are fitted


we don't want to leave them out do we don key

No we dont frankygayboy, no we dont...

 

[Dave Willis]

Who'd be daft enough to do that

[chez]

Tosh - thanks for you reply. I have made 1000l so I'm fairly sure on a 300gpd system that's long enough to "flush it".

Hey. Did you flush the new membrane for a few hours BEFORE you made the 1000ltres? Or were you flushing it as you made the 1000l ? It's just that with a new membrane the instructions should tell you to flush it for a few hours before you start to make pure.
Hope it sorts itself out man!
Cheers Chez