So I will be getting a 160-180 gallon acrylic tank built here soon and need to finalize filtration. I had thought I was going to get two FX6's but now I'm considering a sump. The tank will house a Piraya Piranha so it needs a lot of filtration. What do you guys think? Sump or 2 FX6's? What will the downsides be to a sump? Downsides to the canister filters?