Pure water problems

[Smurf]

Nice one...:thumbsup:

Just remember to back flush the new membranes when you put them in. I'm sure they will come with instructions how to do this but thought I would just remind you if not.

 

[spruce]

You will improve your production rate if you fit a booster pump. However I found that upgrading to 150 GPD membranes worked well. Water production was still slow in the winter but it produced enough to keep two vans 'watered' with a little planning. Our water pressure is 50 psi, but we are at the end of a cul de sac.

 

[Carlton]

Thx again chaps...

Back flushing is now my reason for living. Will also be replacing my carbon a lot more often.

Did you see my post on the previous page?

Interesting that production is slower in winter. My filtration equipment is in the kitchen so hopefully that should help. Wondered about the 150gpd membranes which were just a few quid more but didn't want to get it wrong. Maybe in a few years if all goes well.

Thx again...

 

[spruce]

It doesn't matter where the r/o is kept I'm afraid. If the incoming tap water is colder the r/o production will slow down. The viscosity of water changes with temperature. Water at 0 degrees C becomes a solid. Cold water is more 'dense' so it doesn't pass through the membranes as easily as warmer water does.

 

[Carlton]

Hi everyone..

My new membranes have arrived from Daqua. I've installed them and back flushed for 30mins.

I then switched to product water and left to run for 1 hour.

The current reading without DI is 16ppm.... A bit high I thought, so checked my tap water, it's pretty high today, running at 298ppm. So by my calculations....

298 x 15% = 283.... So I quess the membranes are running at 95% ish...

Not quite what I had hoped for, but what can you do about a poor mains supply...

Any comments welcome....

 

[Carlton]

Sorry...

298 x 95% = 283...

 

[spruce]

I would suggest you do the individual membrane test again and see if one of them isn't performing as the others are. It could be down to the membrane not seating properly in the housing. We use a very thin film of silicone grease on the 2 'O' rings to ensure they slide into their housing without 'rolling' or twisting. We also use a very thin film of grease on the large seal as well.

Some have reported that it takes a while for the membranes to settle down.

 

[Carlton]

Thx Spruce...

I'll let it run for 24 hours and then test as you suggest...

 

[Carlton]

Re tested today 24 hours on...

Tap water is extremely high at 334ppm. Thats the highest I have ever seen... but

Product water is now running at 11ppm, lower than yesterday, so I guess the membranes are now settling down. By my reconning, about 96.5% effective..

 

[spruce]

Please don't think this is a stupid question, but, is your tds meter correct?

I watched someone tear their hair out over a period of time only to find the tds meter was not functioning correctly.

Daqua sell a bottle of testing fluid with a known TDS so you can check your meter.

 

[Carlton]

It's correct.... I have two. One generally reads 1ppm higher than the other..

I suppose they both could by wrong...

 

[Smurf]

Did you by them from a reputable company or fake ones from ebay?

 

[Carlton]

I bought the membranes from Daqua..

 

[Carlton]

Sorry you mean the testers?

One I inherited from the systems previous owner. One I bought from a local winow cleaning supply shop in Sheffield...

 

[Carlton]

I guess it won't hurt to buy another...

Any recommendations?