Water

           Ecology

A water ecology tank can be an endless source of interest for observers. It is an ideal apparatus for studying water creatures, food chains and for understanding the roles of carnivores, herbivores and detritivores or scavengers.

Requirements

• A large clear plastic storage container. This can be purchased in a hardware shop
• Water plants such as Canadian pond weed, duckweed, water starwort, water milfoil and arrowhead
• Horticultural sand and some gravel
• Pond creatures such as, water snails, whirligig beetles, leeches, water lice, water fleas, water spiders, pond skaters, water boatmen, tadpoles.
• Pond mud
• Some smooth river stones
• Plastic tubing

Tadpole

Boatman

Louse

Leech

Diving Beetle

Setting up the Ecology Tank

Wash the sand and gravel thoroughly, before putting them into the tank.

Place about 3 cm of gravel in the bottom with about 2 cm of sand on top.

Use rainwater to fill the tank to within 8 cm of the top. (Pour it onto a piece of stiff cardboard to avoid disturbing the sand). If rainwater is unavailable use tap water that has been left standing for a week.

Add half a standard jar of mud from an existing pond. This will contain the eggs of water creatures and will also provide nutrients for plants.

Make sure the tank contains water snails. Snails keep the sides free of algae and water lice scavenge the bottom. Freshwater shrimp will do this as well.

Add a very small quantity of Canadian pond weed, an arrowhead and some duckweed.

Place the stones around the roots of the arrowhead to keep it stable. Alternatively it could be planted in a small pot.

After Care

Place the tank in good light but not in direct sunshine.

Water beetles, dragonfly larvae and water boatmen are carnivores. These should be removed after a short while, especially if tadpoles are being reared in the tank.

Dead plants and animals should be removed.

If the tank water gets dirty some of it can be siphoned off with the plastic tubing and fresh water added.

N.B. You may need to use a perforated lid, if you have tadpoles in the tank.

Perforated Lid

References

Bugs (Magazine Series).Orbis Publishing, London, 1994
Elsie Proctor: Looking at Nature. . A. and C. Black 1969
Andrew Mitchell: The Young Naturalist Usborne Publishing Ltd., London, 1989
Romola Showell: Learning About Insects And Small Animals Ladybird Books Ltd., Loughborough 1972

Text:Paddy Madden
Illustrations:Eileen Fleming
Editor:Marian Rollins
Web Page Design:Taran Pyper 2013