Corydoras selection for a 15g unheated aquarium

[delta6]

Hello everybody,

After breeding and raising 3 gens of endlers in my 15g tank, I decided to move everything in my 33g tank and do sth different. I was thinking of having a group of 6-10 corys. The catch is that this aquarium is unheated and the room temp of the place where it is located ranges from 65 to 70 during winter (after March the minimum temp rises to 70).

 

Is there any type of cory that would realistically cope with these temps at least until the end of winter? 

[Daniel]

Corydoras paleatus, the Peppered Corydoras, does fine in that temperature range.

[AdamTill]

Pandas would like the temp, though might find the volume on the small side 

[delta6]

Thank you both for the suggestions. Indeed I can find both types at my local fish stores. 

[delta6]

Hello again. I decided after all to put a heater in the aquarium and added a group of 10 flame tetra. 

I will keep the project corydoras for the future..

[delta6]

Hi everyone,

 

coming back to my post from 2021. After all this time I am still with my Endlers, now approx. in the 5th generation.

In the meantime, moved houses, torn down past aquariums and set up other ones.

I am running at the moment 2 nanotanks. One since Dec 2021 (12gal approx.), the second since May 2022 (15gal give or take).

The only fish I am rocking at the moment are endlers and one hillstream loach (the only one left from an initial trio back in 2020).

I have come to a point where I kinda lost interest in continuously raising new endler generations and start to be a bit on the heavy stock side.

So since 2 weeks, I have started to separate males and females between the two tanks in order to slow down and eventually stop new fish from been born. I hope to have that done by autumn at some point. I do not know exactly how long do the females store sperm.

After that I am probably going to keep around 10 males in the 12gal tank, and give all other males and females away. Maybe I could keep the healthiest looking females in the 15gal tank as well in case I want to restart the thing in a year or so.

In the meanwhile, I was thinking again to replace the fish in the 15g tank with corys. And the paleatus variety comes back in mind.

I am getting conflicting information though, on the temperature range from different websites and online sellers at my country.

Having lived in this house during winter, spring and summer, I have seen temperatures from as low as 62F during winter and as high as 80F during summer. 68F would be the most seen temp, especially during the spring time.

The aquarium has a lid and no heater is/will be used. I am running a small inner filter from dennerle (the one advertised also for shrimps and bettas) and a sponge filter.

 

Are cory paleatus still a viable option??

 

 

Edited August 15, 2022 by delta6
typos

[nabokovfan87]

On 8/15/2022 at 8:04 AM, delta6 said:

In the meanwhile, I was thinking again to replace the fish in the 15g tank with corys. And the paleatus variety comes back in mind.

I am getting conflicting information though, on the temperature range from different websites and online sellers at my country.

Most Corydoras that like cool water are going to be in the range of 68-74 with recommendations.  Pandas, Paleatus being some of the more commonly available ones.  Pretty much the way to view it is that the vast majority of corydoras will do ok in that range, but there is planet catfish as a place to search for quality information.

If your tank is at 65, corydoras will tolerate it, but this is also equivalent to keeping them warm. They may not be able to do well at that parameter, but once in a while is ok.

Because it's a smaller tank size as well, I would stick to 4-6 or try out one of the pygmy species as long as temps make sense.

I encourage you to create a journal and post some photos! I would love to see your setup and your tanks and see updates on your adventures with the breeding project and tank setups 🙂 .
 

On 8/15/2022 at 8:04 AM, delta6 said:

Having lived in this house during winter, spring and summer, I have seen temperatures from as low as 62F during winter and as high as 80F during summer. 68F would be the most seen temp, especially during the spring time.

The aquarium has a lid and no heater is/will be used. I am running a small inner filter from dennerle (the one advertised also for shrimps and bettas) and a sponge filter.

Adding a lid will help hold in the heat.  The room might be at a certain temp, but the bottom of the tank where the corydoras are at will be slightly cooler and the tank itself might be slightly warmer than the room temp (potentially) depending on what equipment is running.  When it comes to most of the species that enjoy the cooler temps I would also recommend something like the neo air diffuser or the ziss airstones and add that in addition to any of your other filtration.  It will slightly increase oxygenation and most of the cooler water species seem to enjoy that 🙂

As for your question I have a similar situation but with slightly more extremes.  Temps go from below freezing in winter and currently in the summer it's not uncommon to have 115+ degrees F days. (~46 degrees Celsius)

When it turns to the winder months I add the heater and run it very low.  It is there as a safety valve.  If the air temp or outside temps are ~10 degrees F cooler than safe, it is very likely that you need a heater for the sake of the fish.  For those times when it's very cold, I would recommend running one, setting it to 72 during those times.  You can set it lower in the 68-70 range if need be, but I try to keep mine in the 72-74 range.

If you don't want any heater at all ricefish or white clouds might be a great option!

Edited August 15, 2022 by nabokovfan87
added clarification

[delta6]

Thank you very much for your insightful and meaningful feedback. I want also in the future to keep here a joural with all the updates from the aquariums. Hopefully I will find time.

The alternatives that you have mentioned are very interesting. I have kept in the past white clouds, mainly the normal form and they were ok. In case I find a long-fin variation of the "albino" or yellowish type, I will strongly consider those indeed. Otherwise, ricefish always sparked my interest, although they do not come that often to my neck of the woods, and they typically cost more than 5$ a piece.

From my understanding, not all ricefish can live in aquariums without heaters. Is that correct?

Thank you once again for your time and valuable feedback.

[anewbie]

You mentioned 15 gallon aquarium; about the only thing i would attempt in such a small aquarium would be pymgy cory. In a 33 pretty much any species that like cool water. I personally avoid albino of all species of fishes (including cory) myself as i find them unnatural but many people like them.

Do you have a 33 long or one of the odd shaped aquarium - other than pygmy most cory hang near the bottom and floor space is important. Given your other interest i think you would prefer one of the smaller species (pymgy, habrosus and hastatus). Panda are also a bit smaller but not suitable for a 15 gallon. Many of the other species of cory can get fairly large (remember females are substantially larger than males).

[delta6]

Hi. Thank you very much for your feedback. Indeed, I have a 29 high aquarium that sits in the garage. But at the moment I am not really keen to reestablish and replace the small ones. So pretty much I will continue with the nanotanks. Therefore, I would also tend to the smaller corydoras species as you mentioned. However, the more I read and collect information, the more I am drifting away from corys and going to ricefish or minnows. I want also to look around in my local stores to see what is available in a couple of weeks time when the weather will be cooler.

[Kenneth Carl]

On 8/15/2022 at 8:04 AM, delta6 said:

Hi everyone,

 

coming back to my post from 2021. After all this time I am still with my Endlers, now approx. in the 5th generation.

In the meantime, moved houses, torn down past aquariums and set up other ones.

I am running at the moment 2 nanotanks. One since Dec 2021 (12gal approx.), the second since May 2022 (15gal give or take).

The only fish I am rocking at the moment are endlers and one hillstream loach (the only one left from an initial trio back in 2020).

I have come to a point where I kinda lost interest in continuously raising new endler generations and start to be a bit on the heavy stock side.

So since 2 weeks, I have started to separate males and females between the two tanks in order to slow down and eventually stop new fish from been born. I hope to have that done by autumn at some point. I do not know exactly how long do the females store sperm.

After that I am probably going to keep around 10 males in the 12gal tank, and give all other males and females away. Maybe I could keep the healthiest looking females in the 15gal tank as well in case I want to restart the thing in a year or so.

In the meanwhile, I was thinking again to replace the fish in the 15g tank with corys. And the paleatus variety comes back in mind.

I am getting conflicting information though, on the temperature range from different websites and online sellers at my country.

Having lived in this house during winter, spring and summer, I have seen temperatures from as low as 62F during winter and as high as 80F during summer. 68F would be the most seen temp, especially during the spring time.

The aquarium has a lid and no heater is/will be used. I am running a small inner filter from dennerle (the one advertised also for shrimps and bettas) and a sponge filter.

 

Are cory paleatus still a viable option??

 

 

Paleatus come from Uruguay and many other cool parts of South America. Some of those areas can dip into the 50s, so you are well within range of keeping them unheated. You can even do aeneus, mine are doing well at 62F this winter. 
 

Just make sure to feed them a little less during the winter. They aren’t digesting food as fast.!

[mynameisnobody]

To my understanding, all ricefish do well at lower temps. I have an outdoor tub of platinum Medaka and another outdoor tub of red king yama blood medaka. I never had issues and both tubs drop into the 50’s. Even the fry don’t seem to be effected. 

Edited February 2 by Mynameisnobody

[nabokovfan87]

On 8/16/2022 at 12:05 AM, delta6 said:

From my understanding, not all ricefish can live in aquariums without heaters. Is that correct?

Good question. I haven't heard of any that can't. But just keep in mind that there is "too cold" for some fish. 

 

[Comradovich]

So for your pygmy cory questions, I have actually done research in these as I eventually plan to breed each species.

1. Pygmaeus likes between 71-78 degrees F. These forage on the bottom like other cories, but they also spend time "hovering" in the mid-water and resting on plant leaves. Black neons help coax them out more if your school is shy. Also seem to like following otos. Mine were a joy to keep. They also did fine as long as I was heating the room they were in to a comfortable "room temperature" during the winter.

2. Habrosus likes between 71-78 degrees F. These are pure bottom dwellers, you see them do the little cory dance all over the tank. These make some of the better YouTube videos on corys.

3. Hastatus likes between 71-78 degrees F. These are your most expensive of the little guys. They really like the mid-water if you also have a conspecific tetra. I believe "reed tetra" is the correct one. If it has a tail spot like the Hastatus, it may look enough like the fish to promote mid-water shoaling.

4. There's also Cochui, which like slightly hotter water. These are super hard to find outside of Europe. Supposedly behave much like slightly larger Habrosus. Been trying to get a school before I commit to starting a pygmy cory breeding project, since I can usually source the other three species. I asked Dan's Fish about these last night in the live-stream and he said we were unlikely to find any unless someone takes a huge risk on an import order, (which he was not planning on).

[Lennie]

On 8/16/2022 at 6:51 PM, delta6 said:

However, the more I read and collect information, the more I am drifting away from corys and going to ricefish or minnows.

I'm not sure how well small corys would take colder temps.  They usually prefer 23C or more. Some bigger ones would take a bit lower temps but they are too big for 15g imo.

I keep my pygmy cories in 24C.

Meanwhile I think gold white clouds look great. @beastie has them, and I fell in love when she shared some pics. Definitely on my list for some day.

Edited February 2 by Lennie