not sure

[unexpectedcustom]

I'm not sure weather you'd call this an indoor or outdoor pond but... I'm building a small (8x5) pond in my garage. I live in the south puget sound area of WA. The garage gets down into the 30's but not quite freezing temps. I've got flitration, lighting, and areation figured out. My biggest question is what will it take to heat it. I would like to do tropical fish. I haven't decided what I want in it yet. I'm more concerned with seeing how sucessful the building side of it is first. Also if you have any suggestions as to kidproofing the pond that would be wonderful as well. I'm not concerned with the kiddos climbing in more so with them messing with the equipment. Thanks for the !

 

[Oddball]

Unless you want to see your utility bill go up a few hundred bucks a month, then tropicals are out. You're looking at trying to heat ~750 gallons, probably uncovered, in an unheated garage. Aside from the nearly 4,000watts of heaters, you're trying to heat the pond to 80F from 30F instead of from the 75F in the house.
Your best bet would be to insulate the garage (including the garage doors - they make adhesive insulation batting to fit each section) and weather strip the heck out of all door edges and windows. Then, run a section of ducting from your furnace system to the garage (that's what I did in Vader, WA). Just omit any return to the furnace. Now, you have a climate controlled garage (since it'll also need to be cooled in the summer to maintain when it gets really hot.
I had a thermostatic/automatic vent damper installed, along with the usual manual damper, that closed the duct from the house when the garage was at the proper temp and when the furnace cycled off. This damper kept alot of the garage fumes out of the house when the furnace cycled off. This was a bit of an expense. But, it paid for itself in the first winter of having the heater not running 24/7. Plus, a climate controlled garage added $5k to the value of the house when I sold it (insulating and duct work came to $1200.