Wow! I was thinking EX-3 for a 90gal. Guess the EX-2 should cover it. Thanks!
Some people on Reef Central would put a DAS EX-3 on a 5 gallon pico. The skimmer you purchase should be relative to your feeding habbits and your current or desired bioload (how many fish you (will) have and how big they are... err how much they poo). HTH