We have been using "Pureflo" from Permionics Pvt. Ltd. since Oct 2003 with great results. These are the main factors that influenced us to go for it:
i. Based on reverse Osmosis principle. Has a semi-permiable membrane of pores < 0.001micron dia. A water head of around 10 feet is sufficient to force water through this, getting 100% purified in the process; allowing just the water molucules to pass through. Which also means; if you have saline water; it would remain saline!
ii. Does not use electricity, and very easy to install on existing sinks.
iii. Since the unclean water is forced to an waste outlet tap, opening the waste tap for 2min a day is the only maintenance needed.
iv. Internal tank of 4 ltr. takes 10 min to 30 min. to fill up (based on your water pressure).
v. Company claims water pure enough to be injected into human body.
vi. Permiable membrane needs chemical cleaning once 4 years and costs Rs.250/- Permionics is a Baroda based company supplying blood dialysis equipment for renal treatment (kidney failure); who ventured into water purification, seeing additional revenue in this segment. So the technique is be guaranteed safe! Company supplies similar equipment for paint/refinaries for chemical separation based on molucular size. The advantages it has over other UV lamp based models:
i. These use electricity. If that fails, you can’t purify water.
ii. UV lamp needs replacement every 2 years.
iii. The filteration candle needs annual maintenance that costs Rs. 600/- iv. Water got from this is "sterile". UV breaks RNA/DNA in the micro-organisms making them dormant for upto 48hrs. Water stored beyond that causes them to re-generate. Hence water purified with this technique HAS to be consumed before this time. Cannot be injected into human body! v. Water has to be collected then and there. No internal storage. vi. Relatively expensive installation. I would definitely recommend this one to you. Only verify that it is sold in your city.
Adding Dealer information on request:
(Pune) Shree Marketing; Ph: 020 2525 0978, 020 2523 4621