Is a pond heater a good or a bad idea?

[daver]

I live in Oklahoma where the temps range, on average, from 100F in the summer to 20F in the winter. We are having an unusually cold spell right now with temps running around 5F. My pond is about 700 gals, with deepest part about 30" deep. The fish like to stay in a 30" long 12" PVC cave on the bottom during the winter. Because of a 5-10F degree forecast for several days, I decided to put a small floating heater on the pond to keep the pond from icing over. This morning, I noticed my largest koi (15") out of the cave swimming around. Water temp was 42F. Am I doing harm to the fish keeping the water temp this high in the winter when the fish might be better off hibernating, or is this okay? I only intended to melt a hole for air exchange -- not warming of the entire pond. Should I continue the heater use, remove it, or only use it to melt holes then remove it? Thanks for your expert guidance.

 

[Mmathis]

I’m not going to comment on the heater, because I hope it’s a misprint that you have koi in a 700gal pond! Hoping you meant to say 7000gal. If indeed it is 7000gal, your fish will be fine without a heater. If the surface freezes, then use something to keep a hole open for gas exchange. IMHO, it’s going to be a losing battle trying to HEAT a pond — just keep the surface ice-free!

 

[poconojoe]

I'm not sure if it's bad to "heat" your pond. It's definitely not necessary. All you should need is an opening for gas exchange.
Your fish will naturally hibernate under the ice.
What is the wattage of this heater? You might be using an unnecessary amount of electricity.

I use a floating pond deicer that is only meant to keep a hole in the ice for gas exchange.

Oh, others will chime in on this, but your pond is too small for koi.

 

[daver]

In recalculating, the pond is probably closer to 1,000 gals, but it only has 4 small koi (7", 8", 10", & 15") and a few small goldies. In 5 years, I've only lost two fish, probably to a duck that was visiting the pond at the time. The floating pond deicer is 1,500 watts.

 

[poconojoe]

Here are some other ideas:

An air stone kept up close to the water surface can keep an opening in the ice for the most part, but when the temperatures get into the single digits (Farenheit) for weeks, that can freeze over.

Also, a fountain can keep an opening.
I have a simple homemade fountain/filter. It's a bucket with a small pump in the bottom covered with lava rocks. A piece of 3/4" pvc pipe is screwed onto the pump's output. The pipe extends up to just below the water surface creating a fountain.
This keeps an opening in the ice for most of the winter. If you have a couple weeks of single digits an ice dome can form over the fountain, so it's not totally fool proof.

There's also a device called a pond breather which only uses 40 watts. It seems these are hard to find lately though. A few years ago an online pond outlet that was going out if business sold them for $17, they are normally $79. If you can find one of these, it might be your best choice.

So, these are some ideas. If you can't find a pond breather, a low wattage floating pond deicer would be the next best choice. Get the lowest wattage one you can find. I think the lowest wattage they come in are 300 watts.

 

[poconojoe]

In recalculating, the pond is probably closer to 1,000 gals, but it only has 4 small koi (7", 8", 10", & 15") and a few small goldies. In 5 years, I've only lost two fish, probably to a duck that was visiting the pond at the time. The floating pond deicer is 1,500 watts.

4 small koi can grow into 4 huge fish.
You can keep them if your filtration can handle it, but there's most likely going to be a time when your pond hits a tipping point where it just can't handle all the fish waste.

A 1500 watt deicer is overkill, but that's up to you. The goal is not to heat the pond, only to keep a hole for gas exchange.

It's your pond and you do whatever you like.
Gather all our suggestions and decide for yourself.

 

[brokensword]

In recalculating, the pond is probably closer to 1,000 gals, but it only has 4 small koi (7", 8", 10", & 15") and a few small goldies. In 5 years, I've only lost two fish, probably to a duck that was visiting the pond at the time. The floating pond deicer is 1,500 watts.

15" isn't small and they can get to 30+ inches; Look at the sticky at the top of the Pond Construction forum and note the weights and sizes and bioload koi can achieve; it's a bit eye-opening. Now, I'm not saying to re-home your fish (which should happen before you lose more in the future IF you don't compensate) but will suggest you start planning your LPS entry! LPS; larger pond syndrome--it's real, dude! What this means is that you're probably going to go large in the future, so why not do it before your fish start making your pond hard to manage? Just an idea. Otherwise, as they continue to grow, you're going to have water issues if you don't compensate with really efficient filtration. Consider a bog for this purpose. I know I'm not one to talk (too many/too large fish!) but a small pond is a LOT harder to keep in great shape than a larger one. Another reason to consider 'movin' on up'!!

But trying to heat a pond, even a smaller one like yours, is going to be hard; if you get a decent sized heater, it's going to cost $$$ and you might get the temp high enough to be of value. Especially exposed to the elements, you're now fighting Mother Nature and well, She's been around a lot longer than you, so...my money is on THAT Mistress, ya know? A better idea to keep some heat in is to erect a winter tent to help keep in the earth's natural heat and stop evaporation. Ask me how I know, this...

Your fish should be okay as long as the ice doesn't get as low as the depth of your pond. Anything above ground is much more likely to have this happen and the deeper pond, the better winter (and summer) protection!

Okay, so, get on that idea horsey and 'Let's Ride!'

Ah, soooooooooooooo nice to be able to say that again! Look out 'eyes', I know where ye be a-hidin' now, got my trowel and mortar lined up right next to a bunch o' bricks!!!

 

[daver]

Great ideas all. My pond does have a waterfall, but I turn it off when the temps drop below freezing to avoid freeze-over, doming, and water loss. When the waterfall is off, all of the water flow returns to the pond below surface level, reducing evaporation, causing surface turbulence but little aerification. I like the idea of a pond-breather or other form of aerator. I have felt a little of the LPS already, but the BBS (bad-back syndrome) keeps me from moving in that direction too fast. I dug the 1,000 gallon pond myself with a shovel (approx 10,000 scoops--a lot for a 65 year old), and I have plans for a 2,000 gal expansion and a bog. For those, I'll need to hire some help. I agree the 1,500 watt heater is overkill -- I think I'll order a 300 watt unit. That should melt a hole in the ice handily. Last winter, we had unprecedented temps of -14F for several days and the heater still kept most of the surface iceless. Thanks for all the great ideas. You guys are awesome.

 

[GBBUDD]

Koi can tolerate cold waters with no issues. now if you had cichlids and you had temps drop below 60 i would say yes you need some heat but for koi just keep and area open for gas exchange.

Also agree with 700 gallons and koi being to small

 

[poconojoe]

@brokensword had a great suggestion, create a greenhouse over your pond. You'd be surprised how well that can work.
Some here have done that and the results are a pond that doesn't freeze over at all.

It can be temporary if you like. Just a frame out of lumber or PVC pipe covered with clear plastic sheeting. It won't cost much and not much effort to create. It can be tent shaped to prevent the accumulation of snow.
There are some here that use a pool solar cover for even better solar heat.

 

[brokensword]

@brokensword had a great suggestion, create a greenhouse over your pond. You'd be surprised how well that can work.
Some here have done that and the results are a pond that doesn't freeze over at all.

It can be temporary if you like. Just a frame out of lumber or PVC pipe covered with clear plastic sheeting. It won't cost much and not much effort to create. It can be tent shaped to prevent the accumulation of snow.
There are some here that use a pool solar cover for even better solar heat.

if you want the plastic tent part to last, use Agricultural rated 6mil; supposed to be good for at least 8 years. I figure it's the sun doing most of the harm and in that season, it's not even up! Since I don't get a whole lotta sun in winter, it's probably going to last twice that!

'let's Ride!'

 

[mrsclem]

The 1500w heater is going to kill your electric bill! I have used them in the past. Now it s pond breathers and 100w heaters that have a thermostat. They only come on when the water temps drops too low.

 

[Raza Mehdi]

I live in Oklahoma where the temps range, on average, from 100F in the summer to 20F in the winter. We are having an unusually cold spell right now with temps running around 5F. My pond is about 700 gals, with deepest part about 30" deep. The fish like to stay in a 30" long 12" PVC cave on the bottom during the winter. Because of a 5-10F degree forecast for several days, I decided to put a small floating heater on the pond to keep the pond from icing over. This morning, I noticed my largest koi (15") out of the cave swimming around. Water temp was 42F. Am I doing harm to the fish keeping the water temp this high in the winter when the fish might be better off hibernating, or is this okay? I only intended to melt a hole for air exchange -- not warming of the entire pond. Should I continue the heater use, remove it, or only use it to melt holes then remove it? Thanks for your expert guidance.

A pond heater's merit or lack thereof is conditional on a number of variables and your pond's unique requirements. To aid you in making a well-informed choice, here are some things to think about:
Precipitation and Weather: In colder climates, or if you just don't like the cold, a pond warmer can be a lifesaver.

Water Creatures: Fish A pond warmer is an excellent investment if your pond is home to fish or any other aquatic organisms that are sensitive to cold water. When this happens, a pond heater is often necessary to keep the water at the ideal temperature for the fish.

Water depth and pond size: You may or may not need a pond heater, depending on the dimensions of your pond. When it comes to heat retention, deeper and larger ponds are usually better than shallower and smaller ones. A heater can make up for the diminished effect of natural heat retention in a smaller or shallower pond.

Energy Use and Expense: Think about how much power a pond heater uses and how much it will cost to run it. Particularly in colder regions, heating a pond demands a substantial amount of energy. When considering the financial viability of a pond heater, it is important to take into account the continuous energy costs.

Taste and Personal Preference: For practical or aesthetic reasons, such as avoiding ice buildup or keeping the water feature warm all year round, some pond owners may opt to install a pond heater. When deciding if a pond heater is a good investment for your pond's upkeep, it's important to weigh these aspects against your pond's unique requirements.

 

[j.w]

@Raza Mehdi