Pond Boss Forums PHOTO GALLERY Image Gallery Question on pond draining

Hopefully the photos I tried adding will show up. I am not sure where this post should be placed, but I am looking for some help. This pond was dug prior to me buying. The guy dug a hole in yard and an old field tile ran through it. Pond is 23’ at deepest point. Never stays full until recently. The tile on east end would pull water in and it would suck out the west end and just drain into my marshland.

Last fall I dug the outgoing tile and placed a 90 on it to the surface. This spring the pond filled up and the 90 began pulling water down fine. Then it stopped and the water level was over and flowed into yard. I checked and did not find any reason why.

Yesterday I placed a drain cap on and suddenly water began going down. So what is the reason behind the cap causing the vortex of water? I am baffled. I won’t complain as it is working but I want to understand the reason behind it. Any help is appreciated.

I have had turtles wedge in 4-6" outflow pipes. Maybe your clog cleared itself? I do not use the type of trash guard shown in you picture due to the propensity for clogging. Bar guards are more expensive but are a lot less likely to get obstructed.