Free fish aquarium software for windows

Eye catching 3D Fish Aquarium with realistic fish movements, water caustic effects, bubbles, option to add your favorite picture inside the aquarium, option to play your favorite song/music on the background.. etc.
Visit http://www.screensaverfx.com to download more background images. Over 200,000 downloads already.

3D Tropical Fish Aquarium. Scene 3 animated screensaver features an animated aquarium with bright and colorful tropical fish, corals and underwater plants.

The SimAquarium Opera widget is an aquarium simulation game SimAquarium is an aquarium simulation game - you can buy and sell fish, aquarium sceneries (plants, rocks etc), lighting and other things for your aquarium!
You can play with your fish, feed them and more. To earn money you have to breed and sell fish - there is 28 different species with different characteristics, some of the fishes are very rare.
With more money you can buy bigger and prettier fishes, more impressive aquarium decorations and better lighting. But the most expensive animal you can buy is not a fish - its a dolphin!
The game doesnt need a lot of attention - you can run this game in the background and do something else in the same time (it is possible to reduce the number of frames per second to save processor and you can minimize the widget).
Oh, by the way: you can even take the photos of your aquarium! To take a photo, simply press the photo camera button. If you like your aquarium, you can post the photos here.
Note: To install the widget you have to drag & drop the .zip file on the Opera Widgets Manager window.
System requirements:
- Opera 9 or later

A fish tank on your desktop that needs no cleaning and feeding.
This Widget gets live images from National Museum of Marine biology and Aquarium of Taiwan (http://eng.nmmba.gov.tw/).
The Aquarium is open on Weekdays: 09:00 - 18:00 (GMT +8)and weekend: 09:00 - 18:00 (GMT +8)
(Be sure to see fish or corel at the opening time or you will see complete darkness)
This Widget is modified from The New Yankee Widget of Sean Rankin (Thanks!).

Living Marine Aquarium 2 2.0 is now much more practical than ever, your screen turns into an amazing aquarium with 3D, lifelike fish and other sea creatures swimming above a colorful, moving 3D coral reef. This new version has improved fish movement as well as aquarium sounds and bubbles. Upgrade to the premium version of Living Marine Aquarium 2.0 for 19 species of saltwater fish and sea creatures. You control the type and number of fish in your tank. Two additional coral reefs are available or set to random and your aquarium changes on your monitor.

Aquarium Inutility 1 is an application having the images of nice and crazy fishes swimming into the sea. These make your life more colorful. Keep it on your display and it will keep you company. It is free.