Avoiding (or compensating) the ten most common early fish keeping mistakes.

1. Buying sick fish
2. Improper or absent quarantine / isolation facilities.
3. Overmedication and why people do it.
4. Too-infrequent water changes and why this will kill fish.
5. Jumpers
6. Overfeeding
7. Underfeeding
8. Failure to engineer fish growth into the management of the limnion
9. Inappropriate pond decor and harm to the fish
10. Missing symptoms in sick fish

 This chapter describes the top ten fish keeping mistakes that were not specifically touched on in the chapter which addresses pond keeping mistakes.

 If you know about these most-common mistakes in advance, they will be easy to avoid.

 One of the first mistakes the beginner will make is the purchase of sick fish. Koi keeping tends to be the kind of hobby where folks are impulsive, and they usually have some small amount of disposable income to spend and it burns a hole in their pocket. Without knowing what to watch for, it's easy to buy a sick fish.

 How to buy healthy fish:

First, you should look for active, interested fish. The water in the holding tank should be rolling around and the water's surface should be active. This is optimal for gas exchange and results in healthier livestock. The fish should be cruising below the water's surface and chasing each other around. Don't buy fish which are lethargically hovering in the water.

 The fish should have a torpedo shaped body and by all means the fish should be "fat-looking". Maybe you don't know what "fat-looking" means. This means the abdomen or midsection should be as wide as the head. There should be a smooth contour from the head through the gills and into the body. If the belly of the fish is "pinched" you should not buy the fish. Lame excuses like: "They have been fasted and haven't resumed eating yet" may be offered as an explanation. The smarter move should be to ask that the retailer should give you a call when the fish are eating again, and ready for sale.

 The fish should eat when fed. If they don't eat, don't buy them. If the retailer offers the lame excuse that they were just fed, plan a return trip later to see if their appetite has returned. In case you didn't know, healthy Koi in good water will always eat until they look a little bit like a fat ol' tadpole.