Possible to build a bog filter inside existing pond without emptying?

[Ponds de León]

Need some bog advise... Have a 16000 gallon pond circular pond 4 ft deep with one side tapering to 6ft (formerly an inground plunge pool). Have roughly 100 goldfish and the water is in need of filtration. We live in a rural area so there aren't any pond services nearby, so trying to DIY a bog filter. Could build something external but would need to be large and there is no perfect spot near the pond.

Wondering if its at all possible to install a bog filter within the existing pond without draining??? Like drop some heavy cinderblocks to create a bog zone roughly 15% of the existing pond then add a liner and sink it with gravel to displace the water within the bog area? works in my head but i'm very new to the in and outs of bog filtration. The thought of draining and replacing all that water / creating a holding area for fish seems overwhelming.

Some internet research tells me i need 3-5000 gallons of bog for the amount of fish i have. Does that sound right?

Thanks for reading!

 

[GBBUDD]

Some internet research tells me i need 3-5000 gallons of bog for the amount of fish i have. Does that sound right?

BOG IS MORE BASED ON SURFACE AREA and or the amount o water and fish. yes a bog can be built in the pond but im my area 16000 gallons is three water trucks but whe you build your bog that will take up room bringing your water closer to 12000to 13000 would be my guess

 

[j.w]

@Ponds de León