How to clean an old bowl?

[Phether]

So I found a 3 gallon bowl lying around in my garage for YEARSSsssss now and I'm planning to put a betta in it. Since its been sitting around doing nothing all these years, I'm really concerned about how to clean and disinfect this bowl of anything and everything before I put my betta in there. Any suggestions? Or is rinsing the only thing I can do? Hot water? Any cleaners?

Also, is lighting absolutely necessary for the betta at night when the lights are out? Or is it just for aesthetic purposes?

[Jupiter]

Vinegar works like a charm, mix it with some warm water.

[kelly528]

Lighting is only for aesthetics and growth of underwater plants. If you are not planting the tank, the only time you need to turn the light on is for observing the fish, so don't worry about providing your betta with lighting... they are perfectly happy in some nice, dark water :)

[Phether]

Does vinegar leave any (un)harmful residues? I read that diluted bleach could be used as well since it will eventually evaporate

[dramaqueen]

Vinegar or bleach will work but you have to rinse the daylights out of the bowl. If you use bleach, rinse REALLY well, then sit it out in the sun for a day, then rinse really well again.

[iheartmyfishies]

There are also cleaners that are made specifically for aquarium use.
See link:
http://www.petsmart.com/product/inde...&lmdn=Category