[DaveG]

I've just started using a spectrum membrane in my 4040 ro unit (with booster pump at 80psi), What ratio is yours set at?

Cheers

[Spruce]

I've just started using a spectrum membrane in my 4040 ro unit (with booster pump at 80psi), What ratio is yours set at?

Cheers

The ideal ratio is what your  membrane performs best at.
I have an inline tds meter. The best ratio is when the pure leaving the membrane is at its lowest reading.  This is when the membrane is at its most efficient. With an inline tds meter, its easier to setup.

You might have to take pure samples before di to identify the best ratio with your tds meter.

You might start with 2 waste to 1 pure and go from there.

[DaveG]

Thanks Spruce. It's on around 60 waste/40 pure at the moment and it's down to 005 before resin which I'm more than happy with but wanted to make sure it's not shortening the membranes life.

[Spruce]

Thanks Spruce. It's on around 60 waste/40 pure at the moment and it's down to 005 before resin which I'm more than happy with but wanted to make sure it's not shortening the membranes life.

If you reduce the waste by too much, the tds of your product water (the pure) will increase.  I haven't a booster pump, but with our water pressure and tap water tds, our waste to pure is about 55 to 45. If I throttle the waste back further, the tds rises.
However, if I open the waste further then I can get the same tds of pure at about 70 waste to 30 pure ratio. Any higher and the tds of the pure rises.
So I have a pretty good operating window. However, I set waste as low as possible to save water and extend the life of the pre filters.

[dd]

Thanks Spruce. It's on around 60 waste/40 pure at the moment and it's down to 005 before resin which I'm more than happy with but wanted to make sure it's not shortening the membranes life.

Sounds about right to me.

[DaveG]

Thanks Spruce. It's on around 60 waste/40 pure at the moment and it's down to 005 before resin which I'm more than happy with but wanted to make sure it's not shortening the membranes life.

Sounds about right to me.

Cheers 

[DaveG]

Thanks Spruce. It's on around 60 waste/40 pure at the moment and it's down to 005 before resin which I'm more than happy with but wanted to make sure it's not shortening the membranes life.

If you reduce the waste by too much, the tds of your product water (the pure) will increase.  I haven't a booster pump, but with our water pressure and tap water tds, our waste to pure is about 55 to 45. If I throttle the waste back further, the tds rises.
However, if I open the waste further then I can get the same tds of pure at about 70 waste to 30 pure ratio. Any higher and the tds of the pure rises.
So I have a pretty good operating window. However, I set waste as low as possible to save water and extend the life of the pre filters.

Thanks again Spruce