Koi fry are not growing
Our koi spawned for the first time in the 7 years we've had them. We hadn't planned this and didn't know anything about what to do, so we got on Google and found out as much as we could. We prepared a 50 gal nursery tub with aeration, plants and a screen draped over pvc for easy extraction when the time comes. We moved approximately 75 to 100 fry into the tub as soon as they started hatching. They are now approximately 6-8 weeks old and the majority of the fry moved are only about a quarter of an inch to a half inch in length. The majority of the koi left in the big pond are at least one inch to 3 inches in length, all from the same spawn, as far as we know. The nursery tub is plenty warm and has plenty of oxygen in the water. We cycle the plants out of the big pond every few days so they can get fresh algae which we supplement with crushed Hikari gold pellets. As I said we were not planning on raising any koi babies but since we were thrust into this against our will, we decided we would give it a try. Can anyone give us an idea as to why the fry we moved into the tub might not be growing like their siblings that were left in the big pond? One other thing too, the fry that were left in the big pond are a variety of different colors matching the different adult koi in our pond, while the little guys that were moved all seem to be staying a solid orange color. Also, we are certain these are koi fry, because we have no other species of fish in our pond.