What are the options?
Fortunately in 2020 and beyond technology has offered us a serious helping hand. The answer to that question even a decade ago would have rendered all the options at that time, non-options, simply because of the cost. While today there are three main options open to you, the only real non-option is doing nothing, and not including some form of a temperature management system. Its also a good idea to include your selected option at the planning phase and consider it a capital item, just like the fibreglassing, mechanical or main filtration system costs. Yes – it really is that important.
We’ve included the three options in order, with the least favourable first, and the best option last. To qualify this, our listings are listed in order of efficiency, other factors like size of system and utility availability, might make the actual choice for you.
In-Line Electrical Heaters
This is the simplest least capital expensive option. It’s also the most expensive to run and least controllable. These units are simply installed at a convenient point in the return pipework, after the filtration system, and are tubes with electrical heating elements. Because of their relative inefficiency and running costs, they become quickly impractical as pond sizes increase. However, in systems like treatment or quarantine systems up to 2000 gallons/10,00 litres, they do provide a good option. The bigger the KW heater the bigger the supply cable, and associated connection and isolation equipment, which is also incrementally more expensive with scale. There are no cheap to run electrical heaters and if you choose this option, don’t ever take your eye off the electric meter, and consequential running cost, as they’re likely to be significant.
Conventional Gas or Oil Fired Boilers
This option gained favour in the early days of pond heating in the UK in the 1990s when there were few viable alternatives to electrical heaters. These units are two-stage devices with the heat being provided by either a conventional gas or oil boiler, and then delivered into a stainless steel heat exchanger, placed in the filter or settling chamber. The heat exchanger then acts as a radiator and delivers heat to the pond water as it’s required. By definition, these systems are not accurately controllable and the size of boiler and heat exchanger depends on the volume of the ponds, they’re required to heat.
While the total capital cost of these systems is higher than their electrical counterparts, the running costs are massively rendering the total cost of ownership being significantly less. Even today there are many of these systems successfully running ponds all over the UK, so it’s absolutely an option.
Air Sourced Heat Exchangers
The original design of these systems was as ground sourced heat exchangers. With the mechanical heat exchanger being linked to an underground network of pipework. Water is pumped around the pipework and heat absorbed by the water circulating them is extracted by the above-ground heat exchanger device. Great if you have space but practical limitations and heat exchange efficiency issues, led to the development of the basic technology to enable it to extract heat from the air, rather than the ground, hence the evolution of the game-changing air sourced heat exchanger technology.
The technology was initially driven by the USA swimming pool market where it also proved to be a game-changer, but for many Koi keepers access to this technology finally enabled us to keep Koi as we’d always wanted to – in controlled temperatures.
Trade Secret…
The optimum temperature range for Koi is 12˚C./55˚F to 25˚C/77˚F.
Important: The reason we don’t allow the temperature to drop below 12˚C is that below that their immune response and digestive ability is compromised. Above 25˚C our Koi’s delicate colour phages crucial to their colours, can divide and break down.
Shssssh!
Real Time Update… From Paul 18/10/2022
At the time of writing this paragraph, date above, the World is a very different place, and Britain is facing a cost of living crisis. The reason I write this extension to this informative section, in the resource centre, is there will be some of you reading the above and thinking ‘yeah right’ heating the Koi pond is a no no…. and I understand.
All the above facts are true, but I do want to emphasise on the fact below
Heating is a luxury, not a necessity
It’s true we all want our Koi to thrive, but we have to be realistic here to.
In the early days of my Koi keeping journey as a hobbyist, I didn’t heat my ponds, and I didn’t loose my Koi either, well maybe the odd one. I very quickly learnt one thing though, and this brings us back to husbandry, check your Koi before Winter, and whilst there is a pond temperature of above 13 degrees. The reason I say this is to give you and your Koi the upper hand going into Winter. Check the water parameters and check your Koi for parasites etc… Most treatments are less efficient or cannot be used below 10°C, some cannot be used below 12.5°C. If they are carrying parasites, yes the parasite will be less active in the cold water too, but come the Spring when water temperatures rise, the parasite will have the advantage, above the Koi with a very low immune system.
Prevention is better than cure
Now another important thing to consider, especially if you heat your pond, is to cover your pond in Winter. We use polycarbonate sheets with a thickness of 16mm. These clear sheets are fantastic at locking in heat, without reducing valuable light, and as heat rises, without a cover you would only be heating the sky.
Even if you don’t heat your pond there are still advantages to covering your pond, the main one being wind chill, a cover will afford you a few extra degrees, and will even on sunny days, magnify a little heat. However you must leave a degassing gap, this allows gas exchange and prevents the Koi from suffocating.
Always check your Koi over Winter, and test your water periodically, as things can go wrong, and often do.
