Mine is 27 feet long 4ish feet wide. The one thing I would probably do different, IF I WERE TO DO IT AGAIN, would be to stick with shorter plants.
My obedient , bentomy , mint, yellow flag are all tall, from 4 feet to 5 feet tall. They all tend to fall over during the summer, grow via runners bloom beautifully, filter wonderfully. Nothing short survives.
But I found water willow, variegated japanese iris, bog bean smaller plants that would do great, bloom nicely filter wonderfully.
So if you want a more controlled bog watch what plants you put in.
Mine has shallow areas, low areas, above water areas, the plants don't seem to care.