New Pond Build - Some newbie questions...

[Moneypit]

I agree with oldfish, BD should be plumbed separate for gravity feed. Also, many people use the sump as a settling chamber and a single pipe will force the water in at a higher velocity than two. Your pond is roughly 4500 gallons which requires to be turn one time per hour. That sumps going to be pretty big to do what you want. Lack of mechanical filtration will be a problem not to mention no UV.

I will second this, how will you clean the bottom drain piping when it gets biologics growing on the inside of the pipes if you tee them together? It happens believe me. The other issue is to have a chance of settling out the larger stuff in a settling chamber you should shoot for 10% of your flow, so that would make your settling chamber 450 gallons. If this pond is for koi or any other large waste producing fish you are going to need more filtration, Koi get very large and produce large amounts of waste.