RO Membrane Advice Please

[Natedog]

Hi there, bit of background : I've been pole washing for 7 years now producing my own water with cheap low GPD systems and 10" filters. I have an 1000 IBC tank but only use around 350 litres a day(i work alone sole trader at the moment) I've got on fine with the cheap RO units in terms of how much they produce as I have good water pressure, however my last two 300gpd membranes have not lasted very long before dropping to 80% efficiency and thus eating up my resin polishing to a usable purity.

So my question is, should i just keep buying these cheap membranes or upgrade to an 4040 or 2140 system? I have good water pressure of around 80psi without booster pump. and what is the difference between the 4040 and 2120 apart from size? Is it simply that the 40" produces faster or is it better in any way? 

Many Thanks in advance!

 

[ks789]

Hi there, bit of background : I've been pole washing for 7 years now producing my own water with cheap low GPD systems and 10" filters. I have an 1000 IBC tank but only use around 350 litres a day(i work alone sole trader at the moment) I've got on fine with the cheap RO units in terms of how much they produce as I have good water pressure, however my last two 300gpd membranes have not lasted very long before dropping to 80% efficiency and thus eating up my resin polishing to a usable purity.

So my question is, should i just keep buying these cheap membranes or upgrade to an 4040 or 2140 system? I have good water pressure of around 80psi without booster pump. and what is the difference between the 4040 and 2120 apart from size? Is it simply that the 40" produces faster or is it better in any way? 

Many Thanks in advance!

The 40/21 takes me about 4 hours to produce 500 litres, the 4040 im not sure but maybe produces twice as quick. To get the max longevity out of them follow all the guides on changing of pre-filters and pre flushing system before use etc. Your tap tds should influence how long the membranes should work efficiently for. You will find a lot of previous info on here on this. One of our veterans, spruce knows more than most, though the poor chap has typed many chapters on this over the years. You will find his guidance/info on previous threads ?

 

[spruce]

Hi there, bit of background : I've been pole washing for 7 years now producing my own water with cheap low GPD systems and 10" filters. I have an 1000 IBC tank but only use around 350 litres a day(i work alone sole trader at the moment) I've got on fine with the cheap RO units in terms of how much they produce as I have good water pressure, however my last two 300gpd membranes have not lasted very long before dropping to 80% efficiency and thus eating up my resin polishing to a usable purity.

So my question is, should i just keep buying these cheap membranes or upgrade to an 4040 or 2140 system? I have good water pressure of around 80psi without booster pump. and what is the difference between the 4040 and 2120 apart from size? Is it simply that the 40" produces faster or is it better in any way? 

Many Thanks in advance!

What make are those cheap membranes?

I had 3 x 150gpd Filmtec membranes I purchased from RoMan. They are made in the USA. They lasted 6 years and gave me more than enough water for a single operator when processing into a 1000l IBC tank.

When you buy Chinese made membranes they aren't as efficient and don't last long and it ends up costing you more in time.

As @ks789 says, prefilter maintenance is paramount as is the right pure to waste ratio when producing water.

As the saying in sales goes;

The bitterness of poor quality remains long after the joy of low price is forgotten. I heard that first from an old MD some 35 years ago. Its never more relevant when buying cheap membranes.

A 4040 will produce water faster, but this could also cause other issues. You would have to include a float switch and solenoid valve that will switch off the water supply to the r/o when the IBC tank is full.