I would add a quatic or semiaquatic plants in the dead zones.I am currently running a 3500 gallon koi pond kidney. There are definitely some bad spots with the kidney shape. It creates two separate circulation, but it’s small enough and totally flat so debris always works it way to pump intake.
My thought with this was have two bottom drains one in each deep area. Rather than try to get everything to one end. I figure more is always better
It has been really hot the last couple weeks so waiting until cooler to dig. The property slopes to the right of the photo. The left side is at grade the right will need 4’ of fill. I am debating on wood retaining wall or cinder block fill outside pond on the right. Or just dirt dam all the way. Anybody have thoughts? Or regrets either way.