large old man made pond what to do?

That's half the square footage of a typical new subdivision lot!!

Has it been left to 'go natural'? I doubt a Laguna 3000 will begin to touch it. That's a lot of water. Your filter system would clog so quickly, your head will be spinning. There's a gallonage calculation I need to go look up - I'll do that in a second.

With a 12' depth, there should be no problem in the winter - as long as there is unfrozen water in the bottom. And you can't let the top freeze solid, for air exchange purposes.

If the thing is in poor shape and had no fish in it at the moment, I would suggest a natural approach. Start removing the duckweed manually (with a pool skimmer) and maybe introduce some grass carp to get an ecosystem going. They might just eat the duckweed, who knows? For oxygen, if it needs it, designing a waterfall might be better than counting on a fountain, as the pump to the fountain will probably clog fairly quickly.

Okay LxWxD = cubic feet. 7.5 gallons of water per cubic foot. You have 450,000 gallons of water I will trade you my 300 gallons for it!! The Laguna's flow rate is 1296 gal/hr, so it would take 347 hours to turn over the volume of the pond, if it were even possible. I think it's recommended that you turn the entire volume over once or twice/hr.

I'd rule out something you need to maintain and go natural. It may take some cleaning up first, but get the right plant and aquatic life in there and things should even out and begin to take care of themselves. I'd love to see pics - do you have a digital camera?? Is it dirtbottom, liner, or concrete?? Give me more info - I'm intrigued! The fact that you are breeding mosquitoes tells me that there are probably no small fish living in it. A really cheap way to find out if the water will support life would be to get several hundred minnows or shiners when the farm supply stores sell them for pond stocking (here it's the third week this month). If they survive, they'll eat the mosquitoe larvae, and provide food for anything larger you might want to put in there later. Just a thought.
judy


ps: I wouldn't go wading - someone may have released something in there you don't know about

12 foot deep?? whoa...thats nearly double my height! id fill it in by at least 8 foot if it really is that deep....i dont see a point in having a pond any deeper than 3 foot. the oxygen at the bottom will most probably be near 0, and you would never see any fish down there. a pond the size of yours could do with water lily covering to keep it cool in the summer sun, but you would never get any to grow tall enough to live in your pond. if you were to fill it up, then i would use an inert cement, and even then seal it with a sealant paint to stop it leaching chemicals to be on the safe side. but those measurements have really stunned me...you sure you got them right?

Just goes to show one mans pool is another pond.

How big are the pics? You could email me a couple and I'll see what I can do with them. I'm on cable modem, so download time isn't a problem.
judy

Re: Large old man made pond...

Just how large was the old man that made this pond?

Sorry, couldn't resist

Have you seen 80 Gal Joe's Mysterious Lake thread? I'd be carefull of frozen water in that neck of the woods.