How often do you change RO prefilters.

[Russ]

Hi,
I am making approx. 25 gallons a day of RO water, how long before I have to change my carbon and sediment prefilters?

Russ

[Cosmo]

Russ,

Depends somewhat on the water that's coming in, and the type of carbon your blocks are made out of.

The higher the particulate count in the water, the shorter the life of the sediment filter. One indication it needs changing is your RO output is slowing, but most of the time it just visibly is dirty.

The higher the chlorine/chloramine count in your water the shorter the life of the carbon. RandalB can give you info on how long the different brands of blocks last - from what I've gleaned, coal based carbons about 2500 gallons and coconut based carbons about 4500 gallons. Again, depends on the amount of chlorine in your tap.

You can also tell by buying chlorine/chloramine test strips and occassionally testing your output but chlorine will damage your membrane so you don't want to wait too long.

If you make 25 gal of RO, remember your actually passing somewhere around 75 to 125 gallons thru the filters, depending on your water pressure.

Flush your membrane regularly.. it'll last longer

hth
Jim

[Russ]

Hi Jim,
Thanks for your response, I thought that prefilters would last longer, it looks like I'll need to replace them approx. every 2 1/2 to 3 months.

Russ

[Cosmo]

Hey Russ,

Don't feel bad, I've got to replace mine every 2 - 3 weeks :(

Jim