I've a small above ground swimming pool (12') about 25 metres away from my garage and it's consumer unit. My Plan was to buy some 2.5mm arctic cable to run to the pool area (attaching it to a wall), to provide a single power socket (for garden strimmer etc.), and then 2 swiches, 1 for the Pump and one for the Heater. The heater is 3kw, and I'm pretty sure this cable would be fine. However I've just found the right length of armoured cable, but I'm pretty sure it's only 1.5mm - should I use that, or go with my original plan?