The cheapest and most effective way of heating a large predatory catfish pond?

Polypterus_36

Dovii
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Jan 17, 2021
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I live in Florida where it can get into the 30-33 degree range (rarely), but it normally stays around 50-65 in the winter.
I have a 12-15k gallon pond that I want to heat for some tropical catfish. I looked into some heaters that took up loads of electricity, and they were very expensive.
What type of heater setup have you found to be the cheapest and most effective? Thanks!
thebiggerthebetter thebiggerthebetter
 

jjohnwm

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I've had some success in not-too-bitter winters by shovelling and blowing a thick layer of snow, at least 5 feet or so, on top of the ice as soon as it gets thick enough to support that. This has actually kept at least a bit of water in a liquid state at the very bottom of my pond...but somehow I don't think this will be useful to you...:)

Seriously though, when I was in Ontario (milder than where I live now, but still far colder than your area), a friend and I experimented with a small above-ground pool in his yard. It was round, 12 feet in diameter and 30 inches deep. We built a wooden frame work around and over it, basically enclosing it in a greenhouse-like structure, glazed with sheets of clear corrugated poly. We didn't actually add a heat source, but the sun was sufficient to warm the interior several degrees over the ambient outdoor temperature, and of course the lack of wind was helpful as well. It was only up for a couple of years before his wife decided she had had enough and wanted her yard back :), but during that period the water had only a few brief periods during which it developed a thin skim of ice some nights, while exposed natural ponds were thickly frozen over.

Maybe you could do a similar, temporary structure, or even a permanent wooden type that could have the clear panels removed for most of the year and then re-installed only during the coldest few months? It could probably be made to be an attractive gazebo- or arbor-type thing, perhaps with enough room inside for seating, etc. If nothing else, it would at least insulate the pond and slow down the loss of thermal energy from any heat sources you may decide to use.

I'll mention that we also tried a solar pool blanket, but it was elevated above the water surface on a wooden framework to allow gas exchange. These blankets definitely work on swimming pools when they are on the surface of the water, but we found that it did very little when not actually contacting the water the way we had it set up.

I have no idea if this is a valid idea in your situation, just throwing it out there for consideration. Looking forward to seeing how you solve your problem. Good luck!
 
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Polypterus_36

Dovii
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I think I might try to put a dark tarp over the pond during the winter. That should be able to insulate the pond and keep the temp at a reasonable level.
The only problem is that it is ugly haha, but I guess I will take an ugly tarp over some dead fish.
Thanks for the advice everyone!
 

thebiggerthebetter

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You can use more water to pump into the pond. It may or may not be costly. Many pond people in the SE Florida use water straight from well and increase the water change for colder times. This is the geothermal way.

And as guys suggested above - a pavilion type structure around your pond will bump an average temp by 10-15 degrees F during cold times.
 

Sleepdoc

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The well idea is a good one. I use a deep well to add water to my pond during cold or dry spells. It works well, and my South American cats and cichlids all survive the winters. The well water temp is about 76 degrees year round.

That method, can be expensive though. You end up pumping in a lot of water and a 1 1/2 hp sprinkler pump isn’t very cost efficient. Might be cheaper to run than a bunch of heater though. That however doesn’t include the cost of the well. If you have to get a deep well installed, that’s $$. Shallow (60ft) or standard wells are much cheaper. I tried that but the water was too rusty and I couldn’t see much of anything in the pond. Ended up ditching the shallow and spent 4K on the deep well (175 ft)
 

thebiggerthebetter

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The well idea is a good one. I use a deep well to add water to my pond during cold or dry spells. It works well, and my South American cats and cichlids all survive the winters. The well water temp is about 76 degrees year round.

That method, can be expensive though. You end up pumping in a lot of water and a 1 1/2 hp sprinkler pump isn’t very cost efficient. Might be cheaper to run than a bunch of heater though. That however doesn’t include the cost of the well. If you have to get a deep well installed, that’s $$. Shallow (60ft) or standard wells are much cheaper. I tried that but the water was too rusty and I couldn’t see much of anything in the pond. Ended up ditching the shallow and spent 4K on the deep well (175 ft)
It sounds eerily exactly as it is here on our property. Shallow well pumps rusty water, deep well adequate water after filtering. About the same depths too. And about the same well water temp.
 
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Polypterus_36

Dovii
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Here's some more info on the pond:
The pond is my old pool that I turned into a full freshwater system, so it is made of full concrete. Will this concrete help with the insulation of the pond? It has a pool cage over it which I could try to make into a green house with some cheap insulation material. The tarp covering the pond is definitely going to happen as well.
The pond itself is only going to be 3-5 feet deep in the deep end and about 2 feet in the shallow end.
I planning on putting a group of ripsaw catfish or some other doradids inside.
 

thebiggerthebetter

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Is that above ground or in-ground? Pool cage means minimal work for you to cover it all up but it is usually pretty unsightly. Use UV treated greenhouse film or specialty tarp to cover it up for the winters.
 
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