I have a 5,000 gal. outdoor pond in central California. I have 12 channel catfish in it and 18 Koi. The cats average 10 lbs and the Koi average 4 lbs. Everyone(bosses) wants me to get rid of most of my catfish because they are so big. I just put all the fish into the pond from a larger 220,000 gal. mud bottom pond. The new pond has gravel, bio, U.V., and eight aerators going 24/7. It's crystal clear and ammonia is at .25 with 0 nitr. My question is how long can the cats go without eating? They are used to a crawfish filled pond with all kinds of life. Now they are in a concrete tub basically