Sand

[This Old Spouse]

As I said, a few drops in a large quantity to kill the germs, followed by thorough rinsing in hot water. It rinses clean when done properly. I'd rather kill the germs than risk what might come along with a lizard in my fish tank.

 

[mrp3]

Alright well how do I do it right

 

[This Old Spouse]

If you're THAT uncertain about using bleach, just clean the tank with really hot water. I honestly wouldn't use boiling water because you don't know how strong the seals are on this tank or how old it is. Use a scrub brush or old toothbrush to get into the corners and clean it well, then rinse and rinse with hot water. A 10g is small enough to clean right next to your sink.

 

[Louiseness]

Or you can use hot water and salt instead of the bleach. You still want to rinse it really well though.