newpond,Not sure what Vertex unit you have (Im guessing an Air1) but if it is the cooling fan you are refering to the output of the Brookwood pump will be the same with or without the cooling fan. Moss (algae) is a part of any ponds makeup. Aeration will reduce the nutrients that algae thrive on but will not eliminate it.Desired elimination of algae is a pond owner by pond owner thing.Algae is part of the "life" of the pond and is a good thing managed correctly. Your pond is new and still adjusting. You may also find your water turbid with that many cats in that size a tank.Go through the many posts on new ponds and aeration to get the most out of your pond,Good Luck Ted