Volume of water to # of fish

[woodturner with koi]

I have a small pond (about 500 gallons) . I currently have about 12 to 14 fish of various sizes. Started with 6 or so and over the years have had babies. I was wondering as to the numbers. The pond has been in for 12 years. I was thinking of making a small bog filter. Any suggestions would be great thanks

 

[WaterGardener]

What type of fish?

 

[woodturner with koi]

What type of fish?

Koi, shubunkin and gold fish and I check the volume and it was 525 sorry for the error

 

[WaterGardener]

On this site, it is usually recommended to have 1,000 gallons for the first koi and 500 gallons for each additional koi. The LEAST amount I have seen is 250 gallons for each koi.

For goldfish, the usual number of gallons per fish is 50.

 

[Lisak1]

Agree with @WaterGardener . Far too frequently we hear "everything has been great for years and SUDDENLY all my fish are sick and/or dying. Nothing has changed... what's happening?" What people forget is the one thing that continues to change is the BIOMASS of the fish in the pond. 12 to 14 goldfish are obviously very different than 12-14 koi, but more importantly 12 to 14 SMALL koi are very different than the same fish fully grown.

At this point I would definitely add more filtration if you can - a bog filter would be great. But consider re-homing your larger fish - for their sake and yours.