Tips on how to prolong the life of koi and goldfish?

I have never heard of koi or goldfish eating lettuce or watermelon, however they can live a VERY long time. It is important to know how big your fish should be at its adult size. For some goldfish that is 6"-12" long and for koi up 3'. They are meant to be in outdoor ponds but can be housed in an aquarium. The problem with an aquarium is that koi and goldfish are coldwater fish and prefer to live in water slightly cooler than the ambient temperature in our house. Although goldfish can be housed in large aquariums indoors, It would live much longer and be healthier in general if you had an aquarium chiller hooked up to your aquarium.

If you wanted to keep a goldfish in an aquarium (NOT A BOWL) there is a simple calculation you can use for selecting the right size tank. For most tropical community fish we say 1 inch of fish per gallon of water, however goldfish require more room than that. Goldfish should have 1 inch of fish per 3 gallons of water. So for one goldfish that will live to be 12" long, you should have a 36 gallon tank. For 2 goldfish that get 12" long, a 72 gallon tank should be used. Now I know you think I'm crazy, why would anyone buy a 72 gallon tank for just 2 fish. Well, you did ask how to prolong the life of your fish. If you want you fish to only life a few months, maybe even a few years, then keep him in whatever you want. However if you want your fish to live up to 20 years, they need a big aquarium, or better yet a pond.

Also, an air filter is not required as long as you have sufficient filtration, water movement, and surface agitation. You should have 5-10 times turnover in your tank. For example for a 100 gallon tank, you want a filter that pumps 500 to 1,000 gallons per hour.

Sounds like you are on the right track.

Most important thing is to maintain the water quality. This is what the filter and water changes are for, keep them up.

If they are healthy, they WILL grow, and need a freaking huge tank, or in the case of the Koi, a big pond. As the Koi should grow to 2ft long, you can imagine the size pond they need. Trying to keep them in an undersized tank as they get bigger means the water quality falls off too quickly, they get sick and die.

Ian

Koi and goldfish can live up to around 20 years. Keep up good maintenance and keep them at the appropriate temperature. You can feed them foods such as zucchini, cucumber, peas, romaine lettuce and beet greens although the veggies should be blanched in boiling water so it's soft enough to eat. Cooked squash can also be fed. You can feed them fruit such as bananas and watermelon although you might have to change the water afterwards because it can be messy.

If you really want them to live a very long time get a pond or a big aquarium. What size of tank are you housing them?There is an outlet mall here near my house and they have a koi pond. Some of them are 20"+ long. There are really fun to watch!

If you keep koi in a very large pond they can live and extremely long time they sometimes out live their owners

make sure they have clean water