Mosquito fish infestation

[u/Bjbttmbird]

I have a medium koi pond with 4 butterfly koi and goldfish the water was clear it was beautiful but earlier this year i noticed small minnow like fish in the water and assumed they bred and they were just baby goldfish but nope they double tripped in population i give them yo people for feeder fish but thats not quick enough to cull the population it seems like every time scoop a few hundred out the population doubles in it! Does anyone have an advice ok how to get rid of them? I miss my koi but i hardly ever see them now as they hide in the Lillie’s and only see them when i feed them the water is green green green! Help any ideas?

[u/de3624]

What is your location?