At what temperature do goldfish slow down the metabolism?

[theotheragentm]

I have a nice 2' high x 3' diameter planter, where I keep some goldfish. I believe they hibernate at a certain temperature. The air temperature doesn't drop below 45 degrees at night. That's really low for my area. Even so, do the metabolisms slow down for the fish? Should I not be feeding them or not feeding them as much?

[Bubble_B0y]

here is the answers
http://www.hikari.info/topics/to_07.html

Below 5 degrees celcius (below 41 degrees F) - Stop feeding
Your goldfish should be in their hibernation mode now and no feeding is necessary.

[physicsdude]

Well, overfeding will cause all sorts of problems, like ammonia and nitrite, plus the unsighlty look of debris on the gravel bed. I keep a lionhead goldfish in a 5.5 gallon tank, with a light and such, but he only comes out at night, when the glow from my desktop lamp shines on him! Its weird, I know, but kinda cool as he is quite active then. The temp at night falls to the high to mid 60s.
The metabolisms for the animals would slow down. The temp gauge should be like 2 bucks, then look at the readings at night. If it falls below 60, then I would suggest getting a heater or moving the tank to a warmer location in the house.

[theotheragentm]

I'm a bit confused as the temperature raises up during the day. It is 60 degrees right now with a predicted high of 65 degrees. In a couple days, the high is looking to be 72 degrees. It's only cold at night. The fish swim just fine and are not lying on the bottom most of the time. Are they in hibernation mode?

[DepotFish]

I stop feeding mine at 55F. You shouldn't keep a single goldfish in less than 20 gallons. 5.5 gallons is way too small and I'm sure that planter is too small for more than one fish.

[NeonJulie]

Originally Posted by DepotFish

I stop feeding mine at 55F. You shouldn't keep a single goldfish in less than 20 gallons. 5.5 gallons is way too small and I'm sure that planter is too small for more than one fish.

I don't know about that, some calculations are showing this tank (if it were rectangular) might hold as much as 135 gallons in volume. Now you'd have to deduct for not have corners, but even if that was 10-20 gallons, a three foot diameter tank by two feet deep isn't exactly a flower pot. Of course I don't know how many fish she keeps in it and how the filtration works, but I would say it could certainly keep more than 1 fish.

I would like to see what you base your assumption on as well.

[DepotFish]

I'm basing it on the coffee table fish tank which is 36" in diameter and just under 2' tall. The table holds 40 gallons. Good for two fancy goldfish, but too small for commons or comets to live in for very long. I don't know how many fish she has or whether they are single or double tail, so yes I did make some assumptions.

[theotheragentm]

This is almost a perfect circular cylinder. To calculate volume, wouldn't it be area of the base times the height?

22/7 x 1.5^2 x 2

22/7 x 2.25 x 2

22/7 x 4.5

14.14 cubic feet.

14.14 (cubic feet) ~ 105.79 US gallons

It's been a while since I've been in school, so my math may be off.

[7Enigma]

I think you should keep a heater on all tanks that are not larger than 50-100gallons. The temperature fluctuation is just too great. Large bodies of water such as ponds and huge tanks will not vary significantly from day to night, because the heat capacity of that amount of water helps to buffer the temp swings. Even though the pond is outside and will drop to at or below freezing for a portion of the time its not going 28-36, 36-29, 24-30, its probably varying only a degree or two at most. And once a layer of ice forms it further insulates the water from temperature fluctuations. Small tanks/vases/pots have a much higher temperature fluctuation which is not good for fish, even goldfish which are more hardy than most.

I'm sure they make coldwater heaters that have a lower range than our tropicals. The goal would be to set a temperature slightly above what is expected for the high, and then maintain that level. This way the heater doesn't get overworked, and the fish don't feel any temperature change. Everyone's happy.

[theotheragentm]

I know water holds its temperature pretty well in larger volumes, but a temperature change, even over the whole day, is not good for the fish? If that's the case, you would have to have huge volumes of water in order to hold temperature well. I work for a company that does industrial processes, part of which includes heat exchange and storage. If you're exposed to the environment, you're going to lose temperature really fast unless your volume of water is extremely large, even beyond most backyard ponds.