What size should my bog be?

[Frevis]

Hi all Im looking at creating a swimming pond around 20' x40' and up to 7' deep in spots.

Im just wonder what size bog will I need for a pond this size?

 

[Frevis]

In other words how do I go about finding the right size bog for a swimming pond?

 

[Frevis]

I want to have a swimming pond and then a bog filter off to the side something like this here

So I need to know what size to make the bog based on the swimming pond size

 

[Frevis]

I did find this here

 

[hamstermann]

Typically the advice is that the bog be 10% the size of your pond if it's just plants in there, slightly larger (15% or so) if you have fish as well, and 30-50% if you're going to swim in it. It's hard to get a hard and fast number because it depends on your bioload, how much you'll actually be in it, and how often you want to clean it. (as well as how you build it).

There are also different schools of thought on whether that percentage refers to surface area or total water volume.