Help with heating an outdoor pond

[Savethemall]

Hi, i have a tropical pond of 8000l and im getting ready for the winter. Winter here is pretty average, no snow or anything avergae nights are around 12c ans there are a few rare nights were temps can go less then 5c.

Im trying to find the best way(but also as cheap as possible) to keep the pond around 24c during the winter.
There is the option of getting a heat pump design for outdoor ponds however this is really expensive. Ive been wondering about other options and also been wondering if like 10 of eheim 1000l aquarium heaters can do the job.
If anyone has any personal exp with heating a pond or an outdoor container or has anyinfo about it will apprciate your adivce, thank you

 

[sokolis]

I knew a guy who had a heater from a jazzuzzi hooked up.
All I know

 

[Savethemall]

Jazzuzzi? What does that mean?

 

[sokolis]

Sorry jacuzzi

 

[aldiaz33]

Assuming the Eheim 1000l aquarium heaters are the 300 Watt model, 10 of them would draw 3,000 watts. You'll want to make sure your circuit can handle that much. Not sure where in the world you are located, but in the United States you aren't supposed to run a circuit at more than 80% of it's maximum rated capacity:
1. 20 Amp x 120 Volts = 2,400 watts (max rated capacity) so 1,920 watts should be the max load you should run on a 20 Amp circuit
2. 15 Amp x 120 Volts = 1,800 watts (max rated capacity) so 1,440 watts should be the max load you should run on a 15 Amp circuit
Running more than the recommended wattage on a circuit can create a fire hazard.

Heating large amounts of water requires a lot of energy. Where you can save is if you are able to retain the heat once your desired temp is achieved. For that, a tight fitting cover will be the best way to keep your costs down. Think of it this way: if you are continuously losing the equivalent of 500 watts of energy (heat) from the system, you'll need 500 watts to replace that lost heat. So keeping that heat from escaping in the first place is where you should focus.

I use six 300 Watt Eheim heaters (1,800 watts total) on my ~850 gallon system (aquarium), but it's in an enclosed although unheated room. However, I do have lids and I also insulate the back non-viewing panel to help retain heat. I ended up using around 300Kwhrs/month in the winter to maintain tropical temps. I would imagine at the very least, you'd use double that amount. Find out what your electricity costs are and multiply by 600Kwhrs to get a very rough estimate of your monthly electric cost to heat 8,000L (600Kwhrs is probably on the low end though and could potentially be much more).

Honestly, I'd consider just stocking your pond with species that can tolerate the natural temperatures where you live.

 

[Savethemall]

Heat pumps need much more Watts wnyway.. the smallest one compatible with this pond is 5kw.. so from that point of view 10 eheim heaters are better choice. Anyway im already woth the pond and the tropical fish.. they are rescued fish they dont have anywhere else to be...

 

[aldiaz33]

You might find some info in this video helpful:

 

[Savethemall]

Thanks, temps mentoin in the vid are lower then what i deal. We have here around 2 mounth of full power wonter in which average temp is around 15-20. There are few very cold days in which temp goes below 10 andaybe like 3 stormy nights in a year where the temp will reach 5. All in celsius.

 

[Fishman Dave]

You should be able to get 1kwh heat pump that generate 3-5 kwhr water at 24-26 degrees. Whilst the initial purchase cost is high, (£600 plus installation in UK) the running cost to produce 3-5 kWh is a fraction of tank heaters or koi pond heaters as it’s only drawing 1Kwh.
The logistics of siting and piping are obviously more complicated and there is a yearly maintenance required. There is also the need to have the water flow through the unit but this would usually be from the pump already in use on the pond. Essentially water would go from pump through heat pump and then flow through filtration via gravity back to pond although unfiltered pond water through the heat pump is not ideal.

Unfortunately, these kind of considerations are too late if it’s built already but lining the pond/hole with kingspan insulation would help as would building a greenhouse style double glazed cover (doesn’t have to be glass)

 

[Savethemall]

Can you please explain? What do you mean a 1kwh that generates 3kwh? How is it generating more watts?