What types of fish can live happily in an outdoor koi pond in Southern California?

[Brian K]

I have a ~300 gallon, in-ground koi pond in my yard. It's been home to a couple koi (about 10") and about one hundred mosquito fish for the last year or so. I change out 10-15% of the water each week & keep an eye on pH, nitrates, amonia and salt levels. I have a biological filter system that sprays water in the air to help aerate the pond. Also in there are 3 water lilies providing a decent amount of shade in the summer.

I'd love to put something a little more interesting in the pond (fishwise) - something colorful & not looking like a goldfish or koi. Depending on the fish, I may go out and get a 1000 watt heater which should raise the water temp by about 10 degrees. This means that in the colder months, water temps could dip down to 60 at night (on average) and are generally about 10 degrees warmer by the end of the day.

I've had one recommendation for a giant gourami & one for a fancy plecostomus - neither of which are that appealing to me as they aren't very colorful.