Hmm, you know, I've never once had a nuisance trip from a GFCI on any of my tanks and I've been using several of them for years, both in the wall outlets, and powerbars. The only times they've gone off is when I've spilled water on the powerbars, and I'm glad they did.

Do AFCIs trip easier than GFCIs? I run LED and fluorescent lighting and have an air conditioner in my house.

Gfci and arc fault breakers trip for different reasons. To put it in laymans terms a gfci trips when it see some current leakage as when things get wet and a small current follows the moisture. An arc fault breaker trips when it detects an arc from something like a loose connection. Like I said arc fault breakers are designed for bedrooms as that is where most domestic fires occur. The main cause of these fires was the proverbial octopus. This has become more of a problen over the years as people have more and more electrical items in the bedroom.
If you have power bars and electrical equipment located in a spot where you can spill water on it you should certainly have gfci in place. I have no idea if an arc fault breaker will trip in your specific case all I can tell you they are not recommended in places you have arcing loads. Motors often have brushes which produce an arc, aquarium heaters have contacts which produce an arc. If you are truly worried about your house burning down you should have a journeyman electrician inspect your home and equipment. Electrical installations are more forgiving than most people realize they are often afraid because it is all a big mystery for them. I am more afraid of my tank springing a leak than being electrocuted or having a fire personally.

Or pumps in a Lake, river and streams. Anything near a Pool, Hot tub, Spa and pretty much any place water is mentioned it refers to using GFCI protection. In fact I can count right now 23 different places in the code which GFCI protection is mentioned and required in most of those, with the odd exception. Now sure we don't have a specific rule for fish tanks, but when the trend is water=GFCI it should be a no brainer, ultimately everyone will choose if they want to use one on there tank or not.

On another note

As for AFCI circuits well pretty much useless with water IMO. They are to be used in bedrooms to prevent arcing
pretty simple explanation of them found on Wikipedia
http://en.wikipedia.org/wiki/Arc-fau...it_interrupter


They way I see it a fish tank doesn't really follow any rules in the code, to be safe a GFCI would be great but with lights and pumps plugged in you may get tripping from them turning on and off. If you use drip looks and are cautious then can get away without it. But its to each his own.

Just on a comment on the GFI and Arc Faults. I had a bad connection (made by the electrician that wired my house) with the AF. My digital alarm clock would trip it when it alarm went off.

I have a GFI plug set-up in my tank stand. My Radion lights will trip it, some plugs are very sensitve, and others will be fine. One of these days I am going to replace it with another one to see how it does.