Corys in an outdoor pond

[Andrew.]

I have a 100 gallon pond outside and several 10 gal container ponds. I want to try to breed some kind of Corys outside this summer. They will not have filtration but all will have lots of moss and hornwort. Where I live in the summer it gets to about 70 every day and never rains. I will usually have a week in mid july or august where it will get into the 80s. On the coldest nights it will get down into the mid 50s. What type of cory do you suggest I get? I read on the species page on this forum that paleatus could withstand down to 59F. Would they be the best choice? I would like one that will breed outside, will be able to survive outside, and that I will be able to sell at the end of the summer. Also, will I be able to keep anything in the 10 gallon containers or would they be too small to maintain a relatively constant temperature?
Do any of you guys keep your corys in outdoor ponds? How are yours setup?

[Nabobmob1]

I've done several of the dwarf species and a couple Aspidoras, the only time I've had success was with the addition of some current be it sponge filter or powerhead.

Last year I did

Aspidoras spilotus

and A. sp

C118

in different 55g tubs with a powerhead and hornwart very successfully. Spilotus was the most successful with lots of moss and leaf litter in the bottom, I pulled hundreds of fry come fall when the water temp was in the low 60's to upper 50's

[apistomaster]

I put about 150, month old, Corydoras paleatus in an outdoor pond late one spring.
I harvested them in early September. I used a wading pool about 6 ft in diameter and 12 inches deep. The fry did not grow as fast as they did indoors at 80*F.
It was just for fun and the fry were expendable, had it come to that.
Filtration was via powerhead driven sponge filters.
I live along the eastern Washington border with Idaho at the mouth of Hell's Canyon. It easily lives up to it's name in the summer.
It frequently gets over 115*F during July/August but may get down to -10*F briefly during the winter.

[Andrew.]

Right now I'm thinking I'll probably breed corys inside and grow out fry in the 100 gal pond over the summer. I'd also like to try putting trios in the 10 gals. My pond is across the yard from any outlets so I won't be able to do filtration without running a cord across the yard which is not an option.

[yannick62]

I have put the last summer ten paleatus in a big artificial pond : 1000 liters.
Without air, filter, nothing.....A little of food twice / a week but they have natural food : daphnies and gammares.
In france, the night is at 45-50 F (7-10°C) It's wasn't a porblem......

I have had a very good surprise...... Female have lots of eggs (inside th body), they was enormous.....
Therefore when they came inside the house, they immédiately fry.
They gave 200 egg.
(When they fry inside the home without have past the summer outside they gave 30 eggs max.).

This year, I put all my adult paletus outdoor.
And the babies who have one month old Too but in another tank.

[syno321]

I have kept Scleromystax barbatus outside in a wading pool like Apistomaster for a summer with no problems. They didn't breed but I know that the temperatures fluctuated between 50 and 80, and I'm a lot further north than you. The fluctuating temperatures didn't seem to cause any undue stress, I think because they were gradual.

[Andrew.]

So would paleatus be the best species? Also, could I put a trio in an unfiltered 10 gal?

[Bas Pels]

I would not use one of the small ponds. If they get sun, they rapidly reach high temperatures, over 30 C, and when the sun disappears, the temperature will drop again.

I'm not saying C paleatus dislikes changing temperatures (but I did find more in large pool than in small creeks in Uruguay, so they might not be enthusiastic about them) but I'm saying the expected changes in a small pond will be far too much

[Andrew.]

so what would you guys say the minimum size is? Would a 20 gal work?

[bekateen]

Hi Andrew,

Just a thought... Another consideration about very small ponds is this: Do you live along a flyway for migratory birds? Around my area, friends who put goldfish (and other fish) in small, shallow ponds (I'm guessing about 30 US gallons or less) report losing fish to migrating cranes, geese and ducks. The solution is to cover the pond with something like chicken wire.

Something to consider.

Cheers, Eric

[Andrew.]

There are a few ducks in my area but I've never seen any land anywhere in my neighborhood.

[PabloG]

The bigger is, the lower the thermal fluctuation between day and night. Here in Buenos Aires, the paleatus lives in lakes and small rivers. On winter, the air temp is so low like -1C. I don't know how low the water goes on. I will check this winter.

[yannick62]

I would not use one of the small ponds. If they get sun, they rapidly reach high temperatures, over 30 C, and when the sun disappears, the temperature will drop again.

I'm agree with you.....
But also, when the temperature increase in summer, you see the oxygene lever decrease in the water...
Therefore you have more risk in a little tank.....

Yannick