ashirely If you add a 90 elbow to the inside fitting and turn them up you can add a section of pipe to that and set the water level in the tank to as high as you like. The water from the bog will overflow over the top of the pipe and return to the pond. The fittings inside the tub do not need to be glued, they will stay together well as there would be no water pressure in them.
If I was not about to rebuild my pond I would change my outflow to work like the above instead of a collection pipe with holes in it, much easier to set the water height. Wish I thought of it earlier.
You could have one outfloww higher than the other, one would be the main floww and the other as a backup in case the first gets cloged with plants. When you see water flowing from the 2nd pipe you know the outflow needs attention.
If I was not about to rebuild my pond I would change my outflow to work like the above instead of a collection pipe with holes in it, much easier to set the water height. Wish I thought of it earlier.
You could have one outfloww higher than the other, one would be the main floww and the other as a backup in case the first gets cloged with plants. When you see water flowing from the 2nd pipe you know the outflow needs attention.