avonsurfernc said:I would use both. The more movement of water the better. Of course you need a filter and Biological filter as well for your beneficial bacteria. I would highly recommend a UV clarifier to keep your Algae plumes in check.Hope this helps. Just remember if you hook up a Uv unhook it in the winter months and store in garage or house
giggalz said:i have 40 gallon tub pond preformed liner..that only holds 2 tiny small koi...we are upgrading to 125 gallons..will i need a filter with this? or just a pump to keep things circulating around?