I knew I wanted pygmy cories at some point, and wanted to try and breed them at a later date too, but none of it happened how I planned. Yet things turned out even better than I could have hoped? LOL. I could still do with some input and advice though, since I think the tank might be reaching overstocking levels and I'm going to need to catch and rehome some youngsters. I'm dreading the task of catching and sorting them though. You'll see why when you look at the photos.
Tank talk
This is the first tank I ever bought and set up for myself, and it's changed and evolved a lot since I started it about two years ago. I had planned to tear it down and either sell and replace it, or revamp it (all my tanks have to be moved soon, to accommodate a larger tank) since I know more now than as a complete beginner, and because I'd set it up with this pale gravel substrate, and I'm not keen on gravel anymore, particularly for cories.
This photo is from when I first set it up
Bought second hand, it's a 60 litre/15.5 gallon AquaOne tank with a mismatched, ill-fitting hood. I set up the tank in June 2019, seeded cycle using media and substrate from my dad's long established tank, and this photo is dated from the end of August, 2019. It didn't take long for it to fully cycle, but took several attempts to find guppies that would survive longer than a week... almost made me quit right there. Stock and scape have changed many times since then.
Here is how it looks today;
Current stock is a few male guppies, the elderly and disabled ones left from when I was breeding livebearers (plus three young pretty males I couldn't bear to part with); three otocinclus, many MTS and annoying tiny pest ramshorn snails, and pygmy corydoras.
I hadn't planned to get pygmies yet, but I did something many of us have done, and impulse bought a singleton at the LFS because he was on his own, and I felt sorry for him. I let the store owners know I wanted another batch of them as soon as they could get some, and took him him home, figuring he'd at least have the company of the otos and guppies until I could get some more pygmy friends for him.
I couldn't empty the tank to replace the substrate totally since it was established and risky to switch it out, and the plan was to tear down and rebuild the tank at a later date anyway. So I added a fine sand beach at the front right. Made it into a feeding area as a temp measure until the big tank moves could go ahead. It took a long time to get some friends for him, some supplier problems meant neither LFS had them in stock for months, and when I looked online, the cost of shipping added to the cost of the fish was out of my budget range. So Larry (who turned out to be female, of course!) was full grown by the time I got another batch.
My LFS finally let me know they'd got some pygmies in, but they only had four available. I reserved all of them. When I went to collect, they only had one! Took him home anyway, and skipped quarantine since Larry had been alone for so long, I felt bad for him. The new one was so tiny compared to Larry! Only a baby really. Next I managed to get hold of six juveniles, all looked really healthy, also tiny, and added them too. I lost one of the new ones in the first week, so had seven pygmy cories total. I planned to get another batch when I could, wanting a school of about 12 in total, thinking it was a good amount for this size tank and cories are happier in big groups.
Breeding was the last thing on my mind. I was busy with life stuff, and my livebearers and bronze cories were producing more than enough babies! Since only one was an adult and the others were juveniles, I put the idea of breeding them to the back of my mind. Something I'd want to try as a long term plan, but not at this point. I also thought I would have to try to breed them; that I'd need to condition the adults, that the fry would need careful attention and raising. I never knew that they could take care of it themselves in a colony set up!
Just a couple of months ago, I think it was in May - I was feeding the tank and watching them eat, when a much smaller pygmy appeared! I couldn't believe that it was a baby, and a good sized baby at that... tiny compared to the adults, but it had it's adult colouring, not the stripes that very young fry have. So I knew it had to be several weeks old, and raised itself in the tank, without my knowing or doing anything extra to give tiny food or anything! I was over the moon, but also thought it was a lucky fluke. I've had a bronze cory baby appear in their tank once as well, an egg that I'd missed but had survived, the adults usually eat the eggs, and other fish would pick off the eggs and fry too. There were guppies with the pygmy cories, and I'd heard they are harder to breed than bronzes, so while I was so excited about this baby, I didn't really expect any others to make it.
The next time I did a gravel vac and W/C, I spooked another baby out of his hiding spot deep in the plant growth. Two babies! Then I'd see more and more.... and saw the adults spawning every few days - it seemed constant!
Now, I have no idea how many pygmies are in there. The fry hide all over the place, including down in the gravel at the back (makes substrate cleaning tricky), and under the slate cave that they prefer to sit beneath or on top of, rather than going inside;
When I lift the slate cave, fry of varying sizes dart away everywhere. The adults just keep spawning! I cleaned the substrate two days ago and found a newborn fry, no more than two days old in the bucket.
I dropped an algae disc in here just to show this;
Last time I tried to count, there were roughly 23 good sized ones in there, not counting fry; but it really is impossible to count, since while 23 might be out eating, another dozen could be chilling under leaves or hiding in the dense plants. They do seem to break into 3-4 smaller groups now and again, hanging in different areas of the tank, swimming together etc.
When I first found tiny fry in there, I panicked about how I'd clean the substrate. Gravel holds so much muck; I use a lot of leaf litter/almond cones etc in there which leave a lot of detritus; fish poop falls down into the gravel; gravel isn't recommended for cories; potential for bacterial infections if the substrate isn't cleaned well; and the tiny, insect-like fry are incredibly hard to spot when they're hidden among all that mulm and plant matter at the bottom of a bucket. Also impossible to avoid sucking them up. Have seen babies burying themselves in the gravel when spooked.
On the other hand - when I W/C this tank, I can see seed shrimp and other tiny micro-organisms swimming in the water and muck I've removed. Stuff I don't see when W/Cing my other two tanks. I suspect the fry have been largely living on those, and mulm itself is harmless, right? I love @AbbeysDad 's article on algae, mulm and snails, and I hope that those three things are balanced well in my tank at the moment. The plants are also thriving in the gravel, while I suspect that the roots might be too compacted in fine sand, and not have that mulm and detritus the plants can get from the gravel.
But the pygmies undoubtedly enjoy feeding from and playing in the sand, and often just sitting on the sand section in little groups, looking as though they're having a day at the beach.
I wonder if I have the best of both worlds right now, and I hesitate to tear down an ecosystem that's working for them. I'm tempted to move a batch of the adults to my other, sand only tank and see how they do there, if they will keep spawning the fry have just a good a success rate there. I'm torn on the substrate issue... I know that many people here feel strongly about sand vs gravel, and cories on sand or not. I'd love more feedback, scientific links, personal experiences and advice - anything people would like to contribute or share, if done respectfully of course.
Tank talk
This is the first tank I ever bought and set up for myself, and it's changed and evolved a lot since I started it about two years ago. I had planned to tear it down and either sell and replace it, or revamp it (all my tanks have to be moved soon, to accommodate a larger tank) since I know more now than as a complete beginner, and because I'd set it up with this pale gravel substrate, and I'm not keen on gravel anymore, particularly for cories.
This photo is from when I first set it up
Bought second hand, it's a 60 litre/15.5 gallon AquaOne tank with a mismatched, ill-fitting hood. I set up the tank in June 2019, seeded cycle using media and substrate from my dad's long established tank, and this photo is dated from the end of August, 2019. It didn't take long for it to fully cycle, but took several attempts to find guppies that would survive longer than a week... almost made me quit right there. Stock and scape have changed many times since then.Here is how it looks today;
Current stock is a few male guppies, the elderly and disabled ones left from when I was breeding livebearers (plus three young pretty males I couldn't bear to part with); three otocinclus, many MTS and annoying tiny pest ramshorn snails, and pygmy corydoras.
I hadn't planned to get pygmies yet, but I did something many of us have done, and impulse bought a singleton at the LFS because he was on his own, and I felt sorry for him. I let the store owners know I wanted another batch of them as soon as they could get some, and took him him home, figuring he'd at least have the company of the otos and guppies until I could get some more pygmy friends for him.
I couldn't empty the tank to replace the substrate totally since it was established and risky to switch it out, and the plan was to tear down and rebuild the tank at a later date anyway. So I added a fine sand beach at the front right. Made it into a feeding area as a temp measure until the big tank moves could go ahead. It took a long time to get some friends for him, some supplier problems meant neither LFS had them in stock for months, and when I looked online, the cost of shipping added to the cost of the fish was out of my budget range. So Larry (who turned out to be female, of course!) was full grown by the time I got another batch.
My LFS finally let me know they'd got some pygmies in, but they only had four available. I reserved all of them. When I went to collect, they only had one! Took him home anyway, and skipped quarantine since Larry had been alone for so long, I felt bad for him. The new one was so tiny compared to Larry! Only a baby really. Next I managed to get hold of six juveniles, all looked really healthy, also tiny, and added them too. I lost one of the new ones in the first week, so had seven pygmy cories total. I planned to get another batch when I could, wanting a school of about 12 in total, thinking it was a good amount for this size tank and cories are happier in big groups.
Breeding was the last thing on my mind. I was busy with life stuff, and my livebearers and bronze cories were producing more than enough babies! Since only one was an adult and the others were juveniles, I put the idea of breeding them to the back of my mind. Something I'd want to try as a long term plan, but not at this point. I also thought I would have to try to breed them; that I'd need to condition the adults, that the fry would need careful attention and raising. I never knew that they could take care of it themselves in a colony set up!
Just a couple of months ago, I think it was in May - I was feeding the tank and watching them eat, when a much smaller pygmy appeared! I couldn't believe that it was a baby, and a good sized baby at that... tiny compared to the adults, but it had it's adult colouring, not the stripes that very young fry have. So I knew it had to be several weeks old, and raised itself in the tank, without my knowing or doing anything extra to give tiny food or anything! I was over the moon, but also thought it was a lucky fluke. I've had a bronze cory baby appear in their tank once as well, an egg that I'd missed but had survived, the adults usually eat the eggs, and other fish would pick off the eggs and fry too. There were guppies with the pygmy cories, and I'd heard they are harder to breed than bronzes, so while I was so excited about this baby, I didn't really expect any others to make it.
The next time I did a gravel vac and W/C, I spooked another baby out of his hiding spot deep in the plant growth. Two babies! Then I'd see more and more.... and saw the adults spawning every few days - it seemed constant!
Now, I have no idea how many pygmies are in there. The fry hide all over the place, including down in the gravel at the back (makes substrate cleaning tricky), and under the slate cave that they prefer to sit beneath or on top of, rather than going inside;
When I lift the slate cave, fry of varying sizes dart away everywhere. The adults just keep spawning! I cleaned the substrate two days ago and found a newborn fry, no more than two days old in the bucket.
I dropped an algae disc in here just to show this;
Last time I tried to count, there were roughly 23 good sized ones in there, not counting fry; but it really is impossible to count, since while 23 might be out eating, another dozen could be chilling under leaves or hiding in the dense plants. They do seem to break into 3-4 smaller groups now and again, hanging in different areas of the tank, swimming together etc.
When I first found tiny fry in there, I panicked about how I'd clean the substrate. Gravel holds so much muck; I use a lot of leaf litter/almond cones etc in there which leave a lot of detritus; fish poop falls down into the gravel; gravel isn't recommended for cories; potential for bacterial infections if the substrate isn't cleaned well; and the tiny, insect-like fry are incredibly hard to spot when they're hidden among all that mulm and plant matter at the bottom of a bucket. Also impossible to avoid sucking them up. Have seen babies burying themselves in the gravel when spooked.
On the other hand - when I W/C this tank, I can see seed shrimp and other tiny micro-organisms swimming in the water and muck I've removed. Stuff I don't see when W/Cing my other two tanks. I suspect the fry have been largely living on those, and mulm itself is harmless, right? I love @AbbeysDad 's article on algae, mulm and snails, and I hope that those three things are balanced well in my tank at the moment. The plants are also thriving in the gravel, while I suspect that the roots might be too compacted in fine sand, and not have that mulm and detritus the plants can get from the gravel.
But the pygmies undoubtedly enjoy feeding from and playing in the sand, and often just sitting on the sand section in little groups, looking as though they're having a day at the beach.
I wonder if I have the best of both worlds right now, and I hesitate to tear down an ecosystem that's working for them. I'm tempted to move a batch of the adults to my other, sand only tank and see how they do there, if they will keep spawning the fry have just a good a success rate there. I'm torn on the substrate issue... I know that many people here feel strongly about sand vs gravel, and cories on sand or not. I'd love more feedback, scientific links, personal experiences and advice - anything people would like to contribute or share, if done respectfully of course.
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I don't want to cause that 
I'm just genuinely conflicted and confused, and want to learn more, especially before I have to move the tank and make the decision whether to keep it as is or not.
