How do I cover my pond next to something convenient, clear and cost important for my silver arowana?

I had two clown knives that froze in my one pond. I want to put my silver aro within. What cover should I use to keep the watet temp from dropping and freezing which is cheap and that I can see my aro. The solar type cover is nice but not seethrough. Is perspects cheap.
Answers:    This is a very risky buisness. I cant see you being competent to do this, because the arowana hangs out at the top, where the temperature fluctuates far too much for the arowana to live. they arent designed for cold temperature, so if whatever system you used failed, the fish would be guarenteed to die. I can presume of very few working options, and of those, none would be even remotely close to cheap.
I would just use a radiator or make sure the water is constantly moving. TO clear the water move constantly take a pump and place itin the water so it cause a small hump in the water. THis should keep the dampen from freezing. Just make sure you check on the pond a couple of times a day. Also product sure you don't lose power. Also don't count on the waterfall for keeping it from freezing because the waterfall will freeze.
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