I have a one retic in a 110 gallon pond right now and was thinking of building a larger filtration system for it, I was wondering if it would be better to build a stand to put the pond on and build a sump or make an overhead filtration system for it?
It's a double edged sword.
If you sump it the surface area of the pond makes the sump prone to overfilling. A couple inches in a pond adds up fast. Getting the drain to seal up can sometimes be problomatic. I would think this to provide better overall filtration though.
BUT if you use an overhead style filter you're churning the crap with a pump prior to mechanically removing it, making it much more difficult to remove.