Which RO?

[linuxman]

Hi,

I've read several of the threads regarding water quality and seen good reports on reverse osmosis systems. Looking at the websites there appears to be a multitude of different types. Does anybody have any hints or recommendations?

Thanks,

Martin

[Tha_Reaper]

generally a 3-phase filter is enough. 2 phase is also useable, but i would go for 3 phase for the fact that your main membrane (the expensive part) will last a lot longer with a 3 phase filter.

5 phase is overkill, and expensive.

for the membrane... go for one with small pores. a 190 liter/day membrane will be more than enough for 99% of the people.

[Dicon]

Whatever you decide upon, buy one with a pump.

The water pressure in the UK is generally pretty poor and if yours is below the optimum level for the membrane, you will end up with a much higher waste to product ratio than you would want.

[linuxman]

Thanks for the info. Some more questions

• How do they connect to the mains? Is it a tap connection, or do they require something more permanent?
  
• Can they work unattended?
  
• How quickly do they work?
  

Cheers,

[Tha_Reaper]

1: (for most of the home-systems) you can screw it on the end of a tap, or place it inbetween a pipe leading to your tap (dont make my mistake and place it beween the hot water pipe...)

2: yes

3: that depends on your membrane and your water pressure. the lowest is 190 Liters/day if i'm not mistaken. i have such a system, and my water pressure is 1,8 Bar. for me the filter gives me 20 liters of water in 4 hours time, so effectively 120 liter a day.

Edited June 22, 2010 by Tha_Reaper

[mobile]

Depending on the quality of the feed water, you might want to consider a 4 stage system. This is the typical setup:

1st stage: sediment filter

2nd stage: carbon filter

3rd stage: TFC membrane

4th stage: Deioniser resin

Three stage systems have the first three of the above and will typically remove 95-99% of the contaminants in the feed water. To remove any of the remaining, you will need a deioniser stage. A system with a 'refillable' deioniser cartridge could save some money on cartridge replacement, over that of a system with 'replaceable' deioniser cartridges.

The system is usually permanently plumbed into a cold water feed; however, an adapter is available which fits onto a typical garden hose tap. Many systems are supplied with a 15mm self piercing tap which fits onto the household cold water feed. Be aware that the 'faucet' adapters that some come with are typically only suitable for american style taps. If not permanently plumbed, then you might want to consider adding taps to the RO system input, output and waste pipes, as the TFC membrane should not be allowed to dry out. These are push fit taps are often available from the RO system supplier.

Edited June 23, 2010 by mobile

[linuxman]

I think I have a much clearer picture about RO systems now, thanks. Just one final question; I've noticed that domestic RO systems seem to be either for drinking water or for aquaria. Which system do people normally go for?

Cheers,

[mobile]

I think I have a much clearer picture about RO systems now, thanks. Just one final question; I've noticed that domestic RO systems seem to be either for drinking water or for aquaria. Which system do people normally go for?

Cheers,

I can't imagine there is a difference. One point to note, don't use RO water exclusively as your drinking water because, unlike CPs, humans need minerals.