Raised Pond vs Raised Bog Filter - Is the same pressure exerted on the walls?

[LennyM]

Hi! I'm new to the forum and to the world of ponds. I've learned plenty already just from reading many of the posts. I live in Thailand and am building an in-ground pond and a raised bog filter. My initial question is about the amount of pressure exerted on the walls of a raised bog filter vs a raised pond of the same size. The pond has the weight of the water pushing against the walls. The bog has lots of rock and much less water, and also has water running out the top. Does the rock in the bog mean there is more or less pressure exerted against the walls? Does the water running out the top reduce the pressure on the walls?
It might help to explain why I'm asking. I have a lot of 2 x 4s available for free to build a wood frame for a 3 m long x 1 m wide x 60 cm deep bog filter (10' x 3'3" x 2'). I can find many examples of wood frames being used for ponds of that size, but I don't see any bog filters of that size made with wood framing. So I'm sure I could build a wood frame strong enough for a pond of that size, but would it also be strong enough for a bog filter of that size?