I just got this preformed pond from a buddy of mine. From what he said its approx 400 gallons. When I got it it was so green you couldn't see the fish.....straight nasty just to keep it real. Well to keep a li ng storie short I got it home and installed in a afternoon. Its in my front yard next to our porch. Morning sun and the afternoon gets part sun part shade, all shade at approx 4 give or take a little. I'm new to the pond community so I'm here to get educated. I have about 60 or so small golfish in there now just to establish the eco system. I originally wanted koi but decided to go with shubunkins I have not purchased yet instead. As I have been doing more and more research I have been increasingly getting worried about that pH levels, algae,ammonia levels and just the overall well being of my fish. Its still under construction and will be finished soon. Any and all help will be greatly appreciated. Thank you to all.