Bakki Temp loss?

[MikeM]

It will be interesting to see if there are different views/experiences on this one. I think smaller koi over, say 4", adjust better to upward temperature swings, but fare less well to sudden downward swings. Below 4", I would not express an opinion. Not enough experience.

Your 3.5' depth is fine for moderating temperature swings as long as it is shaded to prevent extreme temperature rise during the day.

[ranskye]

you may be right mike, i bet there may be lots of different veiws on this one.
ill let you know why i believe lower temperature drops are better, hopefully we will hear some other opinions also.
it might be that ive stuck to a few notions on this and made it universal to much of my thinking. warm water is best for happy growing fish, yes, not too warm though or thats when things go wrong and go wrong fast they can.

how i see it is that cooler temperatures are better, not for when all things are going fine but when you are looking at troubles being present.. it buys you time that you may not have otherwise.
if the water is clean and good air is there and flitration is stable, certainly a fish will be happier at a warm temperature, it shows in their eating.
this is an obvious fact that our fish like summer more than winter as they are cold blooded and must wait for temp to allow them to move around.
so if all things are ok, say the waters on the cool side of perfect and you raise the temperature by 4 degrees c then fish does definately fare better.

i think most would agree that anywhere from 22-25 celsius would be a good target, 25 giving the best growth rate. however when ever i get a sick fish, i prefer a lower temperature by a few degrees. even to the point that ive been guilty of turning down peoples tanks a few when the fish are crook..why?
it makes good dissolved oxygen levels more easily obtainable, sometimes if you have crowded situations and warm water you just cant bubble enough air in, also ammonia is less toxic to them in a cooler temperature, if theres ammonia present and the temperature is high and then ph is unstable along with most things.. well when that goes high also, bang theyre in trouble. most chemical reactions go fast with heat.

if its cooler they become slugish but in a sedated kind of way, you have time to sort out the problem, they are more unlikely to cause themselves damage by running around freaking out scared of being handles or chased or whatever..damaged scales in less than good water qualty at temperatures is a bad mix. cool water can make them almost like theyve been aneathetised.
theyre respiration slows and stops them chewing through it in panic mode.
ive killed many many fish through heat, but very few through the cold.
the only time ive done that is when ive got a fish species that handles say ocean or river temperature swings cause theyve evolved there and then ive stuck them in a too small tank outside and the temps gone below tolerable and disease has set in over time and taken them out.
still that seems to happen slow enough to see it happen and be able to correct it, just i was probably a bit in bed under the covers myself at the time. they were a marine and more prone to extremes than the koi.
but yeh ive killed more fish than most people i know..

i always try and harvest in the cool, hot harvests kill fish, sometimes real fast, sometimes they die a bit later. moving fish around i prefer the cool days with less sun and more cloud.
transport is better in cool water, stocking density or time travelled can be extended.
so yes i like cool temperature for sick fish, harvesting and general handling and things like that. the notion is in my head from when fish are in a tight situation, lack of good clean water or high crowding and things like that.

as far as making it cold real quickly yep that may be the problem, i havent noticed any yet but im still learning.
the other day i had someone want some fish, a warm day.
there were fatter healthier fish in a tank - within a pond outside.
the pond surface 8 inches or so was rather warm. stratification going on for sure. there was cool water from the bottom of the pond being pumped as a recirc sytem through the tank giving the fish in the tank some temperature relief.
i netted some fish up, started counting them out in front of the customer on the edge of the pond and they went belly up as i was doing it. errrrrr...um.... sorry .. hangon..lol.

i took them inside and had them nestled in the net in cooler water and they came back good, i counted them all and bagged them up and they were fine again.
whenever i send away fish i put a few small blocks of ice under the bag or a bigger block insulated in the corner of the box to make em survive a long trip.
actually i remeber packing and sending out goldfish, which are very similar to koi, straight from 20 degrees c into a bag of near freezing water and sending them on a plane and they nearly always made it there, no usual mortality except for some skinny ones.
ok thats what ive found anyhow. hope it helps.
akai san, if the water is good quarantine water youll be ok with some temp swings, if its questionable id say keep it in the shade if you can.]
if youve got them in quarantine cause they have got a problem, and them making it out relies on the life cycle of a parasite or something.. make sure the water is clean and oxgenated. if theyre just new fish, make sure the water is clean and oxygenated anyway.

[MikeM]

I understand your thinking, but I disagree with parts. The low oxygen content of very warm water may be a stress factor inducing the reduction in resistance to the disease organism being treated in quarantine. A gradual reduction of the quarantine pond/tank to a reasonable temperature makes perfect sense. Optimal temperatures are in the mid-70sF (around 23C if I remember right?), so that would be the goal in the quarantine, unless heat was being applied as a treatment. As long as extremes are avoided, it seems to me that maintaining even temperatures is important in quarantine, with shifts being gradual. Typically, a shift of a few degrees over the course of 24 hours will not matter. I do get concerned, however, about the notion of taking goldfish from warm waters and dumping them in near freezing water, and then sticking them on a plane for shipment. I would strongly recommend that readers on this board not follow that protocol. The goldfish may have been hardy enough to survive it, but testing limits of endurance is not the way for most folks.

[ranskye]

ha yep mike, that practise was pretty slack, your correct and its good advice you give telling readers not to follow what i did. i certainly dont encourage doing it. that was bad..
i went off the subject of bakki and a way away from quarantine procedure and spoke of an extreme situation for transport when facilities and time didnt allow for it to be done right.
i was saying that it worked for us when we did it, in trying to emphasise that cold water change was my choice over warm.
all so it would back my theory! sorry.
anyone got a situation where raising it is better. lets say even steady temperature of mid 70f/23c is good. definately.

what ive done shouldnt be thought of as good aquaculture practise. a shift from 20c - 2c degrees in one second isnt good for anything. SHOCK is what i comes to mind.
i probably shouldnt be saying more on this but we did keep that customer for over a year, actually my old boss lost them last week due to pricing, they now get supplied cheaper by someone closer hence why we had to pack em so tight and so cool. cheap feeder fish, cheap comets.
100 x 5cm fish in under 1 litre of water.. lucky not to have animal rights on our back..
never had we sent koi like that because they dont allow them into that state. if i had a real expensive koi id step arouund it in socks.

i still like to cool things down though, ive lost too many boxes on a hot day before.
if its to be done it should be done gradually for sure.
slow temperature swings are always the go if you can manage it.

ive raised temperature on fish before to finish off a particlular stage of a parasites life cycle so treatment would work when it became vulnerable.

i reckon that both koi and goldfish are relatively tough compared to most fish ive worked with. even so, one should not think like that or one might lose their fish through complacency.

ive got an idea, i should get off this machine and check on my fish.