We put in a 1500 gal water garden last year, and stocked it with koi, goldfish, and rosy red minows. We now have 5 koi, 4 goldfish, and uncounted minows, and they have all been doing well since last year. I don't think the koi or gold fish are big enough to spawn this year, but the minows are on their second generation. Will I need to thin the minows to avoid overstocking? Also, are the minows a threat to koi or goldfish fry?

The first few years of my 1800 gallon pond, I had hundreds of fathead and rosy red minnows myself. But, predators slowly got to them so I have about 6 left. Nature should take care of the balance. When your goldfish and koi get bigger, they will help eat the younger minnows and their eggs. Rosy red minnows will eat eggs and fry of their own species as well as those of goldfish and koi. Of course, the future parent goldfish and koi will also eat as many of their own eggs and fry as they can manage. Some people did trap and remove some minnows due to overcrowding but I've never had to do it in almost 10 years. My 153 gallon pond has a colony of rosy reds. March 2005 I had 60 some (I count when I clean it out) but this year it was half that so the predators won't let them become overcrowded.

Thanks. There are probably less than 40 full size minows in my pond, so if 30-60 do ok in 150 gallons, I don't have a problem. I'll see what happens to all the tiny ones in the next few months and hope for surviving Koi fry next year.