Have a Separate “Power Meter” for All of Your Ponds and Their Respective Power-Consuming Equipment or, Better Yet, Have a Separate Power Meter for Each Pond.
If your ponds are near your house, then, chances are, all the power-consuming equipment are “wired” to your house’s mains, and it would be difficult (if not downright impossible) to determine how much is the “actual” power consumption of your house alone and how much is the figure for your ponds, let alone for each pond.
But if this pond-keeping “thing” of yours is not just a hobby but also a “budding” business, then it is best to determine the “overall” power consumption of your ponds, and (better still) of each pond, so that you would have a better idea of how much to “price” your fishes, right? To do this, hire a certified electrician who will “wire” power meters for your house and for each of your ponds. This way, you’ll have a better understanding of how much your hobby (or “business”) costs you. Looking at the individual power ratings of each and every power-consuming device in your ponds and making some rough calculations just won’t cut it.