Electrical problems - Fish tank related?

[andsoitgoes]

Hi all,

The only thing I've added to our house in the last year, electric-wise, is... well, a whole crapload of fish tanks.

Wattage wise looks like this (it's approximate, I suck):

Bedroom - approx 800w of fish tank equipment, and things like alarm clocks, ceiling fan, a TV we rarely use, and a mini stereo we rarely use

Family Room - Fish stuff approx 110w - misc stuff: Computer, LCD monitor, speakers, wireless router, TV, receiver, DVD and sat box, including my wii

Family Room 2 - fish stuff approx 240w (100w heater, Eheim 2213, stand flourescent and addl 42w fixture) and that's about it

****EDIT - This isn't the case, it's happened a few times since. It usually comes in batches of 3 or 4, and in about 10 - 20 second intervals.
Now - I just realized that one of my outside lights that isn't in the most sturdy of fixtures has been on for the last week or two maybe. I've turned that off, and SINCE then I don't hear anything, so I may be in the clear.
**********

It is very intermittent (it'll buzz, freeze my computer up a bit, create static on the tv - all in all lasts for maybe 15 - 20 seconds, then stops)

I hope that was the solution, but not sure if it's the fact that my older house is so overloaded due to all this stuff.

Look forward to hearing some opinions!

Nick