[dish]

I need help on RO output.

1) When they give RO rating, eg: 300 GPD is this assuming that the RO is running all day 24 hours?

2) When they quote GPD eg: 300 GPD is this the amount of pure water you get out, or the amount of untreated water that it can process during a day.

3) What is the usual % waste in a very, very hard water area?

Thanks in advance

[Roy Harding]

Sesutton

1. yes 300gal per 24hrs.

2. yes 300gal per day is the amount of pure water.

3. This varies on  what R/O unit you have, some as high as 5 parts waste to 1 pure. Other units 50 x 50 ratio, but these cost more.

Roy

[JM123]

Don't forget that when quoting 300gpd this is usually at 100psi with a water temp of 18-22c, realistically, most folks have a tap output pressure of around 50psi with the water being closer to 10c (average around the year) so more than likely you will only get about 150gpd which is enough for most folks.  Other factors such as tds levels can affect output.  If in any doubt always go for a higher output model.  As before waste is roughly 4x product but can be reduced by increasing backpressure on the system with a flow restrictor.