[[GQC] Tim]

I was reading the Ionics catalogue, and I must say that I'm intrigued by their Pro-6 and Pro-7 system. (Miserly and Green systems as they put it.)

On the Pro-6 page it says it's got an additional High spec sediment filter which makes it possible for a large percentage of reject water to go back through the RO membrane.

The only thing that I can see which is different on the Pro-7 system is that they mention a specially designed sixth filter. In small print they talk about a RO Bak filter.

Question is. How can you use this on your own DIY 4040 or 300GPD RO? What exactly are the filters, and would it be worthwhile to use it? I can imagine the filters not lasting that long. The RO Bak filter, whatever that is, is over £50 in the catalogue. Money saved on water, would be used for having to buy a new filter every now and then.

Any ideas guys?

[Nathanael Jones]

I've been asking for a while what this RO bak filter is, and can't seem to get a straight answer!

I would say that it is possible from what I've read to get a DIY RO setup with only 20% waste,.. but getting down to zero beats me.

To get the 20% waste, you would need a pressure pump on the system, running close to your membranes quoted max pressure. You would also need a minimum of 3 membranes, the second plumbed into the waste line of the first etc. Then the correct flow regulator on the waste line from the last membrane is essential. RO-Man could advise on the specifics, as too much back pressure can damage the membranes.

It would be interesting to find out the TDS of the final waste, and what effect passing it through different filters would have. I'd assume that the TDS would be very high, and that any filter used to clean it prior to recycling through the RO would not last very long.

[alanwilson]

really, how much are you gonna save?

it will prob cost a lot more in the long run, what with the cost of Ionics filters etc.

I'd stick with a simple 4040 setup.

[[GQC] Tim]

I've been asking for a while what this RO bak filter is, and can't seem to get a straight answer!

I would say that it is possible from what I've read to get a DIY RO setup with only 20% waste,.. but getting down to zero beats me.

To get the 20% waste, you would need a pressure pump on the system, running close to your membranes quoted max pressure. You would also need a minimum of 3 membranes, the second plumbed into the waste line of the first etc. Then the correct flow regulator on the waste line from the last membrane is essential. RO-Man could advise on the specifics, as too much back pressure can damage the membranes.

It would be interesting to find out the TDS of the final waste, and what effect passing it through different filters would have. I'd assume that the TDS would be very high, and that any filter used to clean it prior to recycling through the RO would not last very long.

Hm, yea I came sort of to the same conclusion, I haven't actually tested the TDS of the waste in a normal setup. I'm really hoping that someone has the system so we can have a peek inside.

It's one thing buying the filter, it's a whole other thing to buy the filter housing, copyrighted by Ionics, and I don't think they'll just sell us one if we don't have the system.