Ease RO Water Purifier with UV

Details

A wall mounted RO purifier with UV, and a page that prints the two things this category is built on leaving out. The first is the reject ratio, which for an RO is the single most consequential fact there is and is almost never on the box. Reverse osmosis works by pushing water through a membrane and washing the rejected salts away with the rest, so every litre you drink has a litre or three going down a pipe. An ordinary domestic machine runs 1 part to 3, which is 25 percent recovery. This one runs 1 to 1, 50 percent recovery, on a higher pressure pump and a flow restrictor sized to match: 2 litres of feed for 1 litre at the tap and 1 litre to the reject line. Recovery plus reject is the whole of the input and both halves are here. The cost of running 1 to 1 is real and this is it: the membrane sees roughly twice the concentration, so it is changed at 12 months instead of 18 on 500 ppm supply. We would rather you knew the trade than believed there was not one. The reject at 500 ppm feed comes out at about 975 ppm, which is fine for a floor, wrong for most potted plants, and never for drinking. The second is the stage count. A sediment filter is a filter, not a stage of purification, and a machine sold as ten or eleven stages is usually a 5 micron sediment, a carbon block, a membrane, a lamp and a post carbon, with the housings and the taste cartridge counted twice each to reach a bigger number. This machine has five cartridges. Four of them remove something. The fifth is for taste. We could market it as eleven and we are not going to. And the thing a shop will not tell you: if your supply is below 200 ppm TDS, an RO is the wrong machine. It will strip minerals that were not harming you, send half your water down a drain and charge you for cartridges to do it. Buy a UV and UF machine instead. That sentence costs us the sale and it stays on the page.

• Recovery 50 percent, published as 1 litre to the tap and 1 litre to the reject line for every 2 litres of feed, with the reject outlet a separate labelled pipe long enough to reach a bucket
• Input TDS range 200 to 2,000 ppm. Below 200 ppm this is the wrong machine and above 2,000 the membrane will not hold its rejection
• Four treatment steps and one taste cartridge: 5 micron sediment, activated carbon block, RO membrane, 11 W UV chamber at 254 nm, then a post carbon polisher
• The blend valve, stated in full: the membrane leaves the permeate around 25 ppm, which tastes flat, so about 12 percent of what reaches your glass is feed water routed around the membrane to bring the output to roughly 80 ppm. That 12 percent has passed the sediment filter, the carbon block and the UV lamp but not the membrane, and it carries its share of dissolved salts, which is the entire point of it. If your water has a chemical problem rather than a hardness problem, turn the valve to zero and drink it flat. The leaflet says how. Nothing is added to the water at any point, and there is no mineraliser here because a mineraliser is a blend valve with a better name
• The 80 GPD membrane figure is a test condition, not a delivery rate. It is measured at 60 psi, 25 C, on 250 ppm test water, which is 12.6 litres an hour. On 500 ppm supply at 15 C in January it delivers about 60 percent of that, 7 to 8 litres an hour, so a 7 litre tank refills in under an hour. That is not a defect. It is what the number means, and nobody prints it
• UV chamber at 254 nm, 11 W, delivering at least 30 mJ per square centimetre at end of lamp life. A UV lamp goes on glowing long after its output has fallen below a useful dose, so there is an hour counter that calls for the lamp at 8,000 hours rather than a light that tells you it is on
• Standard 10 inch housings and a standard 80 GPD membrane, so nothing here is locked to us. The commonest business model in this category is a proprietary snap in cartridge that only the brand sells, at three times the price of the same media
• Consumables, itemised, because the round number quoted in this category is the pre-filters only and the membrane and the lamp are where the money actually is: sediment Rs 190 every 6 months, carbon block Rs 420 every 9 months, membrane Rs 1,650 every 12 months, UV lamp Rs 620 every 12 months, post carbon Rs 310 every 12 months. That is about Rs 3,500 a year on 500 ppm municipal supply, and the litre counter on the display tracks it rather than a calendar
• Storage tank in food grade virgin polypropylene, BPA free, migration tested on the wetted path by an FSSAI-notified laboratory, which is the one place food regulation legitimately touches an appliance
• Pump at 46 dB(A) at one metre, running only while the tank fills, drawing 36 W filling and 0.5 W idle, under Rs 15 a month of electricity
• 2 years comprehensive on the appliance and 3 years on the pump and the membrane housing. Cartridges, the membrane and the UV lamp carry nothing at all, because they are consumables and a warranty on a consumable is a marketing device
• Spares are