quote from a 2017 thread:
“MitchM: FWIW, if you have any ice cover plus water circulation, your pond will have zero difference in temperature between the top and bottom. The entire water body will be about 32.5F. I have sensors at the 2 foot and 5 foot level and have seen the difference even a little circulation can make.”
I’m in north Idaho, zone 6, with a brand new pond which is not established yet. This summer I inadvertently killed all my young goldfish with overdoses of AlgaeFix, which seemed like a good idea at the time but was not. So the Pond of Death is devoid of fish for this first experimental winter, but the plumbing is all in place and functional. The pond is approx. 10,000 gallons (thank you, MitchM, for your calculations), 5’ deep at the drain, separately valved waterfall, skimmer, drain, and subsurface outflow 18” down and aimed at the surface.
Air temps are currently down to mid-twenties at night, and will get a lot colder. Water in unheated horse water buckets freezes 1/4” overnight. The pond drain is turned off, but the waterfall, subsurface flow and skimmer are all running. No ice on the pond. I check the temps around the surface and at the drain several times a day out of curiosity. (I have a sinking fly-fishing thermometer lying near the drain that’s tied to the bank with fishing line so I can pull it up quickly).
The temps currently around the surface are 37F, and the temp at the drain this morning was 32F.
My question is: Given adequate open surface for gas exchange, can goldfish survive 32F at the bottom?
“MitchM: FWIW, if you have any ice cover plus water circulation, your pond will have zero difference in temperature between the top and bottom. The entire water body will be about 32.5F. I have sensors at the 2 foot and 5 foot level and have seen the difference even a little circulation can make.”
I’m in north Idaho, zone 6, with a brand new pond which is not established yet. This summer I inadvertently killed all my young goldfish with overdoses of AlgaeFix, which seemed like a good idea at the time but was not. So the Pond of Death is devoid of fish for this first experimental winter, but the plumbing is all in place and functional. The pond is approx. 10,000 gallons (thank you, MitchM, for your calculations), 5’ deep at the drain, separately valved waterfall, skimmer, drain, and subsurface outflow 18” down and aimed at the surface.
Air temps are currently down to mid-twenties at night, and will get a lot colder. Water in unheated horse water buckets freezes 1/4” overnight. The pond drain is turned off, but the waterfall, subsurface flow and skimmer are all running. No ice on the pond. I check the temps around the surface and at the drain several times a day out of curiosity. (I have a sinking fly-fishing thermometer lying near the drain that’s tied to the bank with fishing line so I can pull it up quickly).
The temps currently around the surface are 37F, and the temp at the drain this morning was 32F.
My question is: Given adequate open surface for gas exchange, can goldfish survive 32F at the bottom?
