[Wildechild_01]

I typed up an amazing reply here and then my computer froze so... now you get this haha.

Cheap power bars are exactly that and you get what you pay for. With that said plugging 3 MH into any power bar is going to be a bad idea. Yes the outlet on the wall is rated to carry a 15A or 1800W load and so is the wire in the wall connected to it. The wiring inside the power bar is going to be significantly smaller than the wiring in your wall likely only rated to carry something between 5 and 10 amps depending on manufacturer and quality of power bar. Pretty easy to see how putting a few things into a power bar can quickly overload/overheat the power bar without ever causing an issue for the breaker protecting the circuit. The same is true for most readily available extension cords.

Our Tanks can very quickly become a very large electrical demand on the wiring in our homes. Ideally we would be able to run dedicated circuits to them but sometimes that doesn't happen. At the very least you should do your best to plug the higher draw items like MH lighting into higher end power blocks like you would see for home theater equipment as these often have the heavier gauge wiring in them to handle the draw. if you can't do this make sure you keep an eye on things.

In this particular situation I would agree the moisture and salt definitely accelerated the problem but it likely would have happened anyway. This is something I see on a regular basis (at least weekly) with my job. People always overload power bars. If possible we should keep as much of the electrical as isolated from the wet/damp environment as possible obviously without a sizeable fish room this can be pretty tricky.

Just a few other electrical safety thoughts.

If your house is more than 20 years old you should consider having your panel inspected by a qualified electrician who specializes in residential service (working on existing occupied homes) and very likely plan on replacing your breakers. Breakers have a 20-30yr life expectancy under ideal conditions, as they age and stop working properly they will not trip when they are supposed to and this can lead to some pretty serious fire risks in your home. The electrical in your home is just like anything else out there, it wears out over time and needs to be properly maintained to function properly and safely.

Okay I should stop now but just a quick word on GFCI's

Just because there is water close doesn't mean you need a GFCI. If there is a sink, bathtub or shower nearby then yes code says you need it. A fish tank does not require GFCI protection and while it is a good idea for some items I would recommend that items vital to tank survival like pumps and power heads not be GFCI protected as they may cause the GFCI to trip when not needed and if not caught can be disastrous to your system... just my personal opinion on the GFCI matter. Depending on how the burning took place a GFCI may or may not have prevented this melted power bar.