The main purpose of a hood or cover is to keep the fish in the tank, keep foreign objects from the tank and minimise water loss through evaporation.

The most basic of hoods is a drip-tray or condensation cover. Simple, cheap, transparent sheets of plastic which sit on the bracing bars of the tank. Although fairly effective, drip trays are flimsy and after several cleanings will become tattered and scratched. Plastic covers are also not recommended where high intensity, and consequently hot lighting is used. Far more robust are glass sliders. These are panes of glass held in runners which again sit on the bracing bars of the tank. Unlike plastic, glass covers are also very good insulators and are effective at reducing heat and water loss. Both of these covers are fine but not very aesthetically pleasing. For the show aquarium a proper hood is better investment.

Hoods can be purchased in a range of styles and sizes to suit standard tanks and are often designed to accommodate lights. It is worth noting that although aquarium lighting is usually designed to be splash proof, water an electricity do not mix. Therefore a drip-tray should be used in conjunction with a hood. Some points to consider when choosing hoods are: -

• Does it allow good and easy access to the tank?
• Can I feed the fish without removing awkward panels?
• Can equipment fitted with electrical plugs be rooted through holes in the hood?
• Do the lighting fixing points suit my needs?
• Is there room for additional lighting?
• Is there a condensation cover included?

You may wish to constructing your own hood to fit a non-standard tank or incorporate a special design feature but always use a material which can withstand the effects of damp. Wood will need to be treated with a suitable varnish to prevent rot and warping and remember to check that the varnish will not harm fish.