200 gpd 10 inch pre filters how often to change

[Deleted member 11517]

Hey how often should I be changing pre filters.

90 psi

I make around 1500 litres a week.

Pre filters are all 10 inch


Mainly the carbon filter ik now sure on as I know they probably don't last long.

 

[spruce]

You really need to tell us what carbon block filter you are using @Bob1980 .

Different manufacturers quote different usage figures. For example, Fiberdyne 10" filters have a service life of 37800 litres. Some have a service life of 6000 litres while others quote a service life of 10,000 litres.

The service life of a carbon block filter includes both pure and waste. So if you were using 1,500 litres of pure a week and your waste to pure ratio was 2 waste to 1 pure then your water usage is 3 litres, not 1.

The only way to know when to change your prefilters is to put your r/o on a water meter. I change my Fiberdyne 20" c/b every 77,000 litres, or approx once every 3 months.

The service life of a carbon block filter will depend on how much chlorine is in your water at any given time. If the chlorine in my tap water was half of what the spec is based on, then in theory my c/b filter should last twice as long. I don't know how much chlorine is in my water at any given time, but I have found that using the manufacturer's spec my 4040 membrane is still working to a 97% rejection rate after 10 years.

The first r/o I purchased was from a windie in our area. The r/o was a year old and he had never changed the prefilters. The membranes were shot. So I know I can't leave my prefilters in my r/o for a year without damage to the membrane.