Retrofit bottom drain to bog?

[AubreyG]

From what I gather it is not advised to run a bottom drain straight to a bog. By straight, I mean without running through a settling chamber or other prefilter for the chunky waste products. Theory is that a bog filter should be focusing on dissolved organics vs visible organics. Clearly you wouldn't want anything entering the bog that would clog the dispersal pipes, but a stainless steel basket on the bottom drain will still pull fish waste through but leave twigs/leaves/rocks/etc.

But why?

Nitrifying bacteria takes care of chunky waste too, albeit slower. The gravel in a bog provides mechanical and impedes flow which allows it to stratify. So one could argue that a bog with a false bottom is a settle chamber, provided that can be flushed.

Is this school of thought more because bottom drains are primarily used on heavily stocked koi ponds that don't utilize bogs or just that it really is a no-no?

(thought brought to you by "it's false spring and I know I can't start in the garden and pond yet but I want to, so time to scheme up improvements" brain)

Edit- I imagine a lot of this is likely impacted by bio load, other maintenance, etc. I personally have a 1,300-1,400 gallon pond with 2 dozen fancy/non-comet goldfish. I hate my pond vac with a passion and am looking to streamline pond chores. Which, if all the mulm is pulled into my bog and I can just turn a ball valve to do a water change & remove excess organics at the same time, that will save me wrestling and cussing at my vac.

 

[GBBUDD]

iN THE SPRING WHEN YOU fire up the pond for the first time The pond is far from being it's best. more algae than usual amounts of algae are going to be thus i do have bottom drains and i have them running direct to my external pump. and with the external is a basket strainer, this is all that is needed for my bog. it grabs the leaves twigs and any algae clumps. this is perfectly fine to be it before the bog.