The best place to install your booster pump depends on the carbons you are using. If you are using a carbon block, after the pre-filter set has 2 advantages. 1. no extra pressure on your clear canisters (safety) 2. more pressure to the membrane ( no pressure loss across the prefilter set) BUT if you are using (my favorite) loose packed carbon you want the pump before the carbon, carbon fines are not good for pumps.
