You have one of 2 things going on. Either your GCFI is getting more
sensitive which is causing it to trip. Or you have a cap going out on
one of your ballasts. What you should do to check is try only running
one halide at a time and see if it still trips. that way you can
isolate it down to either one ballast or the GFCI.

One suggestion I would have for you is redo your tank wiring, having
everything on the same GFCI is very dangerous for your tank. If
anything goes wrong you loose all power to your tank, which normally
means you loose all life in your tank after a while. Move atleast a
couple of filters/water movement devices to another circuit so that you
will not loose everything.

Kim

Hi folks-

I've got an established tank with (among other things) a pair of metal
halide lights in a Hamilton hood. Nothing has changed with the setup in
more than 5 years.

Everything electrical for the tank is on a GFCI (ground fault circuit
interrupter) circuit. The metal halide lights are on a timer (a hard-
wired one, not one of those little plug-in jobs) on this circuit.

All of a sudden, about a week and a half ago, when the lights turn on,
it immediately pops the GFCI and I need to reset it. This has happened 3
times now over the last 10 days. It's a real problem because I travel,
and losing power to the filter isn't a good thing.

Given that I haven't changed anything in years, what could be causing
this all of a sudden?

Some theories:

1. The MH bulbs (a couple years old) are aging and perhaps for some
reason one of them is causing a ground fault when it's dead cold?

2. Maybe the timer itself is getting defective and causing the fault
when it clicks over?

3. Problem with the MH transformer? This is my less-likely theory at the
moment.

Not only is this an annoyance, I'm about to put the house on the market
and I need to resolve this quickly! Time is flying.

Any thoughts or experiences would be greatly appreciated.

Sincerely,

Marc