Before u buy one buy a voltage stick put just the tip in your water or on the glass even and see if it lights up if it does you need one if it dosent you dont have a ground problem

Mike, just plug a power bar into the GCFI and put your timers on that.

Be careful about stringing powerbars together. Jamming all your equipment onto a single GFCI is asking for it. Better to distribute the equipment amongst several GFCIs so if one goes, your whole system doesn't. I keep the absolute essential equipment - the pumps/powerheads - on their very own GFCI circuit through a CanTire UPS.

I see I wrote "timers" I meant just the one Mike could not plug into the can tire GCFI