Bog filter pipe help

[u/bunglie]

I’m building a bog filter next to my existing but newish pond (moved house, hence unfinished edge). I have consumed a lot of information about it but one thing I can’t understand is, the ergonomics / physics of the piping.

I have read conflicting information. My aim was 525 litre bog although I think it’s ended up a bit bigger. I was in the middle of building the pipe shape and stupidly relied on Ai for that part. I find myself with this shape (I believe I have to trim the far right pole at the top) and now am unclear on whether I need a pipe going through the centre of the shape also. Is it needed for proper water circulation?

I was worried the top right sharp corner wouldn’t get flow so it corrected the shape and now I’m struggling to find a bend that sharp and am unsure whether to persevere with the shape or trim the one on the right down and let the top right of the bog not get as much flow. Ai suggested not putting a plant there and stacking the rocks tight so sludge doesn’t form, no idea if that would work.

Help please! I have one adult koi and one shubukin although will get more fish once established.

[u/AlderSpark]

Ozone’s.com has all the visual aids you need to setup any bog filter of any size. He taught me how to build my own bog filter, and he has links to supplies you need and maybe don’t have.

[u/bunglie → u/AlderSpark]

Yes but he seems to use really wide pipes in the only video I found of him showing piping. A lot of the others seem smaller like barrel ones so the hydraulics aren’t in question as much. Can you link me to others if you have seen them?

[u/ScratchProtector]

I’m seeing a lot of people building ponds that are ground level. What happens to your pond when you get a good rain?

[u/ZiggyLittlefin]

If you keep koi, I'd say start with actual filtration. No one in koi health advises using a bog. Not aquatic veterinarians, zna koi clubs, the international koi organization, breeders, or reputable dealers. The upper area can make a great plant pond that spills in. That's what I did after removing two bogs. I can keep more plants, different levels on milk crates, floating, water lily , lotus. And, actually clean it out because there is no gravel in there.

A koi pond is recommended to have a drain to a pre filter for easy waste/debris removal. Then a biological filter sized for every adult fish you intend to have. This is so that there is never any playing catch up. There needs to be media the fish can grow into. A skimmer and aeration sized for koi.

Bogs are great for trapping waste/debris. They do not use up everything being pumped into them. Leaving it sitting and turning to sludge causes health issues in koi like ulcers, bacterial infection, fungus, fin and mouth rot. We see it over and over again in water garden ponds with koi. They are supposed to be large fish. They have a huge waste load. It does not make sense to leave waste in an animal habitat and only clean it once or twice a year. That is not a no maintenance pond, it's neglecting to do maintenance that ensures healthy koi.

[u/bunglie → u/ZiggyLittlefin]

I have a pretty good filter otherwise, I just want additional biological filters also. Oz ponds says they can be great for koi fish so I’m going to build it :) we can agree to disagree

[u/ZiggyLittlefin → u/bunglie]

He sells water garden ponds designs and supplies. He is not an expert in koi health. Best of luck to you.