[karygate]

on my previous filter i had pre membrane a 5 micron filter for dirt and a carbon block filter . on my new 300 gpd i have a 5 micron , a carbon block and also another one which i think is a gac one. do you need this one or iss it just for drinking and fish water.

[[GQC] Tim]

Extra protection for your membranes really, removes chlorine, which is necessary. The more the better, 4040 RO prefilters usually have a 20' carbon filter, usually on 200 and 300GPD's you've got two 10' filters, one carbon block, and the other granulated carbon filter.