Advice on RO/DI Unit

[Laz]

Apologies if this is in the wrong section. I'm looking at four RO/DI units and need some advice. There's four very different prices and wanted to know what would probably be best, or if another one would be better suited. The links are below.

http://www.osmotics.co.uk/products/Ultra%2dPure-4-Stage-50-Gallon-Per-Day-RODI-System.html - £92

V2 Pure 50 Reverse Osmosis Unit (Online Only) | Pets at Home - £89

4 STAGE WITH DI AQUARIUM REVERSE OSMOSIS SYSTEM UNIT MARINE DISCUS FISH | eBay - £40.99

3 STAGE AQUARIUM REVERSE OSMOSIS SYSTEM UNIT MARINE DISCUS FISH | eBay - £20.99

My questions being, are these any good? If so which one more than the others? Is there any frequent replacement with one over the other two which could turn out to be costly?

Any advice would be appreciated. Had enough of going to the LFS for RO. Too much effort.

 

[Barch]

Personaly I would go with the first one:
http://www.osmotics.co.uk/products/U...DI-System.html - £92
It has better pre-filtration, with the bigger filters they will last longer and provide better filtration. Also seems like it is built a little heavier than the other models. A 50 gpd production rate is going to provide plenty of water in a relatively short amount of time. Knowing what your TDS is pre-treatment will help you know what to expect after treatment. Most RO's will only remove up to 95% of the contaminants which will leave the DI filter to remove the rest. Knowing this will help you determine how long your DI filter will last so you can keep your post treated water at 0 TDS.

 

[Laz]

Thanks for looking, Barch. The advice is much appreciated. :)

 

[atony4688]

I had the same questions until I came across Bulk Reef Supply. I bought this unit:
BRS 4 Stage Value PLUS RO/DI System - 75GPD - Bulk Reef Supply
Took me 10 min to set up and ran 1 hr to flush it out. then a day and a half later i had enough water.