Finding a leak

[Dano5478]

Lots of water in my basement and it appears to be coming from the water heater but no clear indication as to where exactly it's coming from. Any tips for tracking down a leak?

Also what the heck is this? Pooled up next to water heater, some kind of bacteria? Dangerous?

 

[frodo]

you have pipes on top of your watr heater, if they are not leaking than, you need a new water heater