Hi everyone! Thanks for all the info! I am looking for help on my pond in general. Before I make drastic decisions I would like to see what others think :)

Pond is maybe 1200 gallons, can't remember the pump's gph but I think it was for up to 10 or 15 ft waterfall? It shoots water out so fast it's annoying. It's 3' deep at the deepest, has a shallow end, never had an algae problem but there is a bunch of crap at the bottom. Last summer I put in a bunch of goldfish, 6 small koi and made a huge mistake in the fall :( I topped off the pond with tap water and the next day everyone was dead. I scooped out all I could find and turned the waterfall off for the rest of the year and left the pond alone. All the plants died and sank to the bottom and I didn't care anymore. Forgot about the pond for the winter and just kept thinking I will fix it in the spring and do everything right. Well a couple weeks ago I went out to look at it, can't see the bottom, but I am ok with that.. but then saw a grey fish about 8" long swim by! One of them survived! So i turned the pump back on, took out the tropical lily pot and scooped up a bunch of leaves and decaying plants from the bottom. There were tons of frog eggs attached to the leaves from the bottom so I scooped them into a big jar of pond water and now I have 50 or so tadpoles in the house. I wanted to leave the rest of the crap at the bottom to eventually turn into silt or whatever and have a natural pond, since the frogs love it and call it home now. I also found a bunch of mayfly larvae and I left them to eat the decaying material. At first I wanted a natural pond like this, and thought I should leave it alone and let nature take over. Now I am thinking I should filter it.

I did add more fish after I had the water tested and it was fine. slightly acidic, but not bad. I also added 2 red ear sliders and put in minnows for them to eat. I know it seems like a bit much for a small pond but everyone seems happy. I just dont want to kill anyone again. Will this skippy filter really work? Should I clean up the remaining leaves from the bottom? I just dont want to disturb it any more than I have to. I prefer to not see the bottom of the pond, so the raccoons can't also! Sorry this is so long, Please let me know if you think I should build a skippy and what should I do about the leaves and the crap at the bottom? AND will this pump that sprays water out so fast work with a skippy filter? Or should I buy a new one that doesn't pump water out so fast.. I really have no idea..

Thanks!