Mystified by sudden fry death

[Karen B.]

Greetings 

I have been raising Clown killifish for few months now. They don’t grow fast, but I don’t seem to have a high mortality rate so I was happy.

However lately I added some corydoras eggs just before they would hatch (you can tell as you can see the fry in the eggs) and for a few days, things seemed fine. The first Cory baby was about 5 days.

However I don’t think my method is the best. I raise my clown killies in glass container with some floating plants and air line. The glass container are placed in a bigger tup which is heated.  I am always afraid they won’t find their food so I put lots of baby brine shrimps in their container. Then twice a day I syphon the dead shrimp, add more water and put some more shrimps. But it’s quite clear I overfeed. But no death happened.

Last night I didn’t have live BBS so I added some that I had frozen. This morning I didn’t have time to change the water, nor feed them. I could only do it around 7 pm and my biggest Clown killifish was dead and so were all 4 of my baby corydoras. So I guess it’s my fault - overfeeding, bbs that were already dead (frozen), no wc, probably a buildup of ammonia but none of my other smaller killies were affected… so that was kinda strange?

I am always afraid my fry won’t find food and will starve.

As for corydoras, if you have any tips, I was never able to raise them. Only time I ever had fry was either when I didn’t even know there was egg(s) on a plant, throw it in my wc bucket, neglect it and find them like 3 weeks later. Or let them in my main aquarium but now that I have female gourami, I don’t see corydoras fry anymore. Basically, the less I do to raise them, the more successful I was… but as now the tank trick isn’t working, any tips?

Thank you!

[Fish Folk]

I recommend going to Walmart. Get this over by the storage container area:

Then build a flow-through by adding a flotation collar and sponges on handles.

The unit will float, place an airline / airstone in. Add Java moss. Very similar to Dean’s fry system.

When you water change, it floats down and then back up with the tank surface water. I’ve been raising German Blue Ram fry this way. I also overfeed, but the flow through keeps ammonia from overtaking the container.

Another far more tedious process can be followed in this long thread here. My son bred Corydoras Aeneus for BAP awhile ago. There might be a trick here or two… but it’s a LOT of work…

 

[Fish Folk]

I’ll add… this container was on sale at my Walmart this week. It is not good-grade, per say, but it is what I used above. I think I got two for $10. This stuff tends to appear as spring season comes and folks get the spring cleaning bug.

I’d also recommend using a coarse sponge for the flow through handles rather than a more dense matten sponge.

Coarse:

Fine / dense:

I just find that the coarse let’s water circulate through better.

[Karen B.]

On 3/25/2022 at 8:50 AM, Fish Folk said:

I’ll add… this container was on sale at my Walmart this week. It is not good-grade, per say, but it is what I used above. I think I got two for $10. This stuff tends to appear as spring season comes and folks get the spring cleaning bug.

I’d also recommend using a coarse sponge for the flow through handles rather than a more dense matten sponge.

Coarse:

Fine / dense:

I just find that the coarse let’s water circulate through better.

Greetings!

Thank you so very much for all this helpful information. 
Just one question - can fry swim through the sponge or get stuck in it? ?

[Fish Folk]

On 3/25/2022 at 11:30 AM, Karen B. said:

Greetings!

Thank you so very much for all this helpful information. 
Just one question - can fry swim through the sponge or get stuck in it? ?

If fry are exceptionally small, it may be possible. However, Corydoras fry would be of no concern to me.