Above ground goldfish pond in NJ?

[ChefConfit]

So we should be finishing work on my basement in the spring and we're starting to think about our plans for our yard. I'd like a large pond (did a patio pond last summer and will again this year) where I live an above ground pond is much simpler to put in because of permits. I'm conserved about being able to overwinter goldfish in an above ground pond though. 

Is there a minimum depth/volume for an above ground pond to be safe for overwintering fish? I'm in zone 7. 

Also would white clouds be able to overwinter in my climate?

[StanF]

I found a good article on overwintering goldfish in an outdoor pond at a site called thepondguy dot com.  It recommends a depth of 18 to 24 inches and a pond de-icer / aerator.  The article is called Overwintering Koi and Goldfish in your pond.  Not sure if I can include a link here, but if you do a search you should be able to find it.

I would be concerned about it freezing over as it does get pretty cold here in NJ sometimes.

StanF

[ChefConfit]

I've read that article before, but I believe it's specific to in ground ponds and meant for a warmer climate because that depth isn't even below the frost line in NJ. I know for here the recommended depth is 4ft for in ground ponds which gives you a foot beneath the frost line.

[igalysh]

I live in Northern Virginia. I have a 800 gallon open stock tank that is all above ground. Even with all the really cold days with early mornings less than 20F and several days not getting above freezing, my tank hasn't frozen solid. I still see my goldfish in there. This is my second winter with the tank. I have a 1200 watt floating deicer and I have had up to a half inch of ice on half the tank. I also have an air powered filter running. Last winter the tank froze over the deicer making the only opening. Being 8 feet wide, I think the ground underneath doesn't get cold enough to freeze the water from underneath.

If I get a chance, for next winter, I'll try to build up a wall around the tank to provide some insulation and make it look nicer.

 

[Beardedbillygoat1975]

I think @igalyshhas a good point about insulation. As you stated obviously you’ll not be able to get below the frost line so creating a pocket of air around it will help. On YT LRB was using spray foam around the tubs and rocks over that in his outdoor above ground ponds for years. 

[Patrick_G]

I have a above ground goldfish pond here in Western Washington. My local koi Store/farm highly recommended a 3’ deep above ground pond both for freeze and predator protection. Most of their above ground ponds are 3-4’.