combat1

  • Posts: 887
RO question
« on: November 11, 2014, 11:55:36 am »
I have two 150gpd membranes one above the other.
TDS reading after membrane one is 15
TDS reading after membrane two is 15
Is this correct? I thought it might have dropped.
The waste from the first chamber goes through chamber 2
I think this is a recycling process to use less water.
Cheers.

Ian Lancaster

  • Posts: 2811
Re: RO question
« Reply #1 on: November 11, 2014, 02:48:07 pm »
When water goes through membrane 1 the waste will have a much higher TDS than the input water as it now has all the impurity in it from the pure water that has gone to your holding tank.

Membrane 2 has to remove all that extra impurity so if it still manages to bring the TDS down to the same as membrane 1, it is doing a lot more work.

This means membrane 2 will not last as long as membrane 1.

You can change this by splitting the input water so each membrane gets fresh tapwater, this will increase your waste production but lengthen the life of your membrane.

The choice is yours

combat1

  • Posts: 887
Re: RO question
« Reply #2 on: November 11, 2014, 10:19:09 pm »
Thanks Ian, actually I bought a higher spec booster pump today from Vyair and the guy there asked me if the waste went into the second membrane.
I will have to work out a split and even things up.
Grateful for your help

Chris

Spruce

  • Posts: 8366
Re: RO question
« Reply #3 on: November 11, 2014, 10:43:55 pm »
Thanks Ian, actually I bought a higher spec booster pump today from Vyair and the guy there asked me if the waste went into the second membrane.
I will have to work out a split and even things up.
Grateful for your help

Chris

Use a couple of JG Tees. I expect they will be 1/4" for the pipe.

http://www.gardinerpolesystems.co.uk/acatalog/john-guest-1-4-inch-equal-tee.html

You will have to join the waste pipes together as well before the flush valve/tap.
Success is 1% inspiration, 98% perspiration and 2% attention to detail!

The older I get, the better I was ;)

combat1

  • Posts: 887
Re: RO question
« Reply #4 on: November 12, 2014, 09:32:10 am »
Thanks Spruce, as always you are a star!
Now I'd better just check!!
After the booster pump fit a jg tee and split the water to each of the two membranes.
Other end connect waste from the two membranes into another jg tee and into main waste pipe?

Does splitting the input to the membranes alter the pressure?
Thanks very much.
I am ugrading my system at the moment, found out my booster pump was not powerful enough for a 300gpd unit, also fitting softening resin chamber, carbon block filter and larger resin vessel.
Should be a lot more effective.