In addition to good filtration, your filtration should have a way to backflush to wash away fish poop and other things that did not get broken down. The DIY filter I made, I put a ball valve to back flush and I now do that once every 1-2 weeks and that also facilitates as a water change.
Up until this spring, my water has always had a fish smell and a lot of foam since I moved in, now with better filtration and a easier way to do maintenance the fishy smell is gone and no more foam (foam = dissolved organic carbon (fish poop, protein, etc))
I've seen posts that people with good filtration and weekly 10% water changes have overstock ponds. I've heard people say rule of thumb first koi is 1000 gallons and each additional koi 200 gallons of water to 10 gallons per inch of fish (what a few pond stores here say) so I guess there really isn't a true answer since ponds are all different. From what I've learned here is test your water and test frequently. I guess if there are any issues with a overstock pond you will see it in your tests.
By the way, when I moved in last year the 3 koi's were about 3-4 inches. Two of the kois about 8 inches and on is 6 inches long after one season! They grow fast!
Up until this spring, my water has always had a fish smell and a lot of foam since I moved in, now with better filtration and a easier way to do maintenance the fishy smell is gone and no more foam (foam = dissolved organic carbon (fish poop, protein, etc))
I've seen posts that people with good filtration and weekly 10% water changes have overstock ponds. I've heard people say rule of thumb first koi is 1000 gallons and each additional koi 200 gallons of water to 10 gallons per inch of fish (what a few pond stores here say) so I guess there really isn't a true answer since ponds are all different. From what I've learned here is test your water and test frequently. I guess if there are any issues with a overstock pond you will see it in your tests.
By the way, when I moved in last year the 3 koi's were about 3-4 inches. Two of the kois about 8 inches and on is 6 inches long after one season! They grow fast!