Welcome to Koi Forum. Is this your first visit? Register
Results 1 to 11 of 11
  1. #1
    Senior Member Rank = Mature Champion smartin's Avatar
    Join Date
    Mar 2019
    Location
    East Sussex
    Posts
    2,373
    Thanks / Likes
    5042

    Winter heating quandry

    Good morning,

    I hope your all well,

    I am currently running the pond at 15c fish fine eating and active etc, i am in two minds wether to maintain this temp throughout winter or to turn off the ashp and let the ambient temps do what they please...... my stupid overthinking brain says no keep them warm as they have never been below 14c before as i worry that they might suffer if getting down to say 6c as they have never experienced this before, if i turn off the heat now and looking at next weeks ambient temps the pond will fall roughly a degree in 24/48 hours as temps between 5 - 8c for the week? so pond could go from 15c to say 8c within a week to ten days? is that too much of a drop to quickly ? any thoughts / views appreciated..... then on the other hand i have read articles where its deemed good pratice to allow your fish to over winter heatless... thanks Steve


    2200 gallons,infinity window,BD
    Evolve 4k combi,amalgam UV
    2x20k pondxpert, Skimmer,
    shower,ASHP

  2. Thanks davethefish1 Thanked / Liked this Post
  3. #2
    Senior Member Rank = Supreme Champion RS2OOO's Avatar
    Join Date
    Feb 2018
    Location
    South East
    Posts
    5,438
    Thanks / Likes
    12183
    Quote Originally Posted by smartin View Post
    Good morning,

    I hope your all well,

    I am currently running the pond at 15c fish fine eating and active etc, i am in two minds wether to maintain this temp throughout winter or to turn off the ashp and let the ambient temps do what they please...... my stupid overthinking brain says no keep them warm as they have never been below 14c before as i worry that they might suffer if getting down to say 6c as they have never experienced this before, if i turn off the heat now and looking at next weeks ambient temps the pond will fall roughly a degree in 24/48 hours as temps between 5 - 8c for the week? so pond could go from 15c to say 8c within a week to ten days? is that too much of a drop to quickly ? any thoughts / views appreciated..... then on the other hand i have read articles where its deemed good pratice to allow your fish to over winter heatless... thanks Steve
    How about reducing gradually to 10C and see how the fish are, then go from there. If they are ok let them down to 8C and re-evaluate. I find below 8C you start to see signs from one or 2 that they are unhappy, but they should still cope with it.

    If well insulated it doesn't take a lot of energy to maintain 8C at all.

  4. Thanks Manky Sanke, smartin Thanked / Liked this Post
  5. #3
    Moderator Rank = Supreme Champion Feline's Avatar
    Join Date
    Aug 2013
    Location
    Somerset
    Posts
    6,632
    Thanks / Likes
    5602
    I think with the current energy costs, there is more reason than ever to question the temp your paying to maintain and whether it is worth it.
    What is your aim with heating to 15C? Its too low for feeding for growth. It’s a touch low for full immune system function. It’s high enough for parasites to multiply though if there are any around.

    If you do decide to reduce your temperature, I would advise doing it gradually. Reduce the thermostat by 1C every 3-4 days until it gets down to whatever temperature you choose.

    I’m currently not heating my pond like I usually would at this time of year- I heat to 23C through to the end of august to keep feeding heavily, then slowly decrease it down in November and December. This year the pond is covered and has slowly fallen and is now at 12C unheated.
    I would personally heat if it falls below 8C as I hate to see miserable fish hanging out on the bottom (and I can see their little miserable faces through the pond window from inside the house ).

    I tend to think of heating as having zones for different purposes:
    • To feed for growth (optimal growth is over 20C, if you overfeed below this you might find fish use it to get fat not bigger)
    • To reach the right temperature for a medication- some require min 16C to use them.
    • To prevent fish suffering from the cold- our ponds don’t have temperature stratification like a natural lake due to pumps turning over the water and mixing it. The minimum temp any wild fish would experience would be around 4C. Koi are less hardy than their wild counterparts so I believe even 4C is too cold. You will have to decide for yourself whether you believe in keeping the pond out of ‘aeromonas alley’. I’ve kept my pond at 8-10C for a while in previous years and never had an issue with that, but your pond might vary.

  6. Thanks Manky Sanke, samp09, smartin, MalNorwich, sammy66 Thanked / Liked this Post
  7. #4
    Junior Member Rank = Tosai stormstorr's Avatar
    Join Date
    Oct 2020
    Location
    West Sussex
    Posts
    21
    Thanks / Likes
    32
    First winter with an ASHP - so much conflicting advice around. I am covered and maintaining 16C until Christmas. Plan is to drop by 0.5C a day until I reach ambient temperature (4/5C) and then wait until the beginning of March and slowly raise back up to 16C.

    10 month 'summer' and 2 months 'winter' to help cleanse the pond and help reduce any parasites/ bacteria.

    Will see how that goes - and how the fish react.
    2,700 Gallon Pond, Infinity Window, Aquasource Synergy 35 Drum, 12Kw Thermotec Invertor, Amalgum UV.

  8. Thanks samp09, smartin Thanked / Liked this Post
  9. #5
    Senior Member Rank = Mature Champion smartin's Avatar
    Join Date
    Mar 2019
    Location
    East Sussex
    Posts
    2,373
    Thanks / Likes
    5042
    Good evening,
    thanks for your replies......

    Having thought more on the matter today and reading your replies i will start to reduce gradually, with 8c being the lowest target, thanks Steve and Feline.....good luck Stormstorr with your winter plans....
    2200 gallons,infinity window,BD
    Evolve 4k combi,amalgam UV
    2x20k pondxpert, Skimmer,
    shower,ASHP

  10. Thanks RS2OOO, Feline Thanked / Liked this Post
  11. #6
    I’m covered and usually heated, not currently heating, temperature sitting at 14.7, I’ve found I may lose at the most 1 degree overnight, lower the temperatures go the slower the pond temperature falls, can take three or four weeks to get through the aeromonas alley.

  12. Thanks Feline, smartin Thanked / Liked this Post
  13. #7
    Senior Member Rank = Hassai big h's Avatar
    Join Date
    Feb 2016
    Location
    East Yorkshire
    Posts
    768
    Thanks / Likes
    1020
    Im in the process of enclosing the pond with big windows and a tiled roof.That will help with temps.Ive always heated to around 9 degrees,never had a problem.Fish seem happy at that and the wife still talks to me when we get our electricity bill so win win in my book

  14. Thanks smartin Thanked / Liked this Post
  15. #8
    Senior Member Rank = Rokusai Naoki Atsumi's Avatar
    Join Date
    Dec 2020
    Location
    Tokyo Japan
    Posts
    452
    Thanks / Likes
    303
    The premise behind most Japanese people's choice of no heating during the winter months is that they are fed to the limit during the summer months to accumulate nutrients.
    As mentioned in another thread, late autumn is the most critical time for completing them.
    I am aware that those are difficult in the light of UK business practices and annual schedules.

  16. #9
    My pond which is uninsulated, uncovered and fully in ground is now at about 8C.
    Being in "thermal contact" with the subsoil means that it will go down to about 6-7C and stay there unless we get a very cold snap.
    If it goes below 5.5C I have simple 2.4kW (81p/hr) electric heating.
    Last year the heating was on for about 12hrs in total through the Winter.
    The most relevant point here is that at these low temperatures the fish do lie on the bottom most of the time (no window so only see this if I look) and slow right down when they do swim.
    I try and avoid anthropomorphising their behaviour and demeanor - easier to avoid guilt pangs that way.
    However, my last pond had no heating at all and I kept koi like that without related issues for over 20 years.
    My DIY ponds from 1988 until present day.
    All can be found here:
    https://www.ukzero.com/pond.htm

  17. Thanks smartin Thanked / Liked this Post
  18. #10
    Extreme Koi Member Rank = Gosai sammy66's Avatar
    Join Date
    Dec 2014
    Location
    swindon wilts
    Posts
    269
    Thanks / Likes
    355
    Hi all , my first winter with the heaters going off the last 5 years i kept them at 18c this year going down to 12c may go to 10c with the heaters . THE KOI HAVING TO GO WITHOUT THIS YEAR

  19. Thanks smartin Thanked / Liked this Post
  20. #11
    Senior Member Rank = Grand Champion davethefish1's Avatar
    Join Date
    Apr 2019
    Location
    Bedworth
    Posts
    4,670
    Thanks / Likes
    9627
    Quote Originally Posted by smartin View Post
    Good morning,

    I hope your all well,

    I am currently running the pond at 15c fish fine eating and active etc, i am in two minds wether to maintain this temp throughout winter or to turn off the ashp and let the ambient temps do what they please...... my stupid overthinking brain says no keep them warm as they have never been below 14c before as i worry that they might suffer if getting down to say 6c as they have never experienced this before, if i turn off the heat now and looking at next weeks ambient temps the pond will fall roughly a degree in 24/48 hours as temps between 5 - 8c for the week? so pond could go from 15c to say 8c within a week to ten days? is that too much of a drop to quickly ? any thoughts / views appreciated..... then on the other hand i have read articles where its deemed good pratice to allow your fish to over winter heatless... thanks Steve
    i'd just play it by ear mate,
    see how the fish are as you lower temperatures.

    my heating is set to 13C at the moment, but the pond is still at 15.5C no heating on for the last couple of weeks.
    i'm just setting it as a back stop if we have a cold snap. and temps plunge.

    but i would probably leave the window cover on if it got down to 8C and hold it there,
    but mine didn't go any lower than 12C with no heating last year...

  21. Thanks smartin Thanked / Liked this Post
 

 

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
All times are GMT +1. The time now is 08:12 PM. Online Koi Mag Forum
Powered by vBulletin® Version 4.2.3
Copyright © 2023 vBulletin Solutions, Inc. All rights reserved.

vBulletin Improved By vBFoster® (Lite Version), © UltimateScheme, Ltd.