The normal hatch time for C. aeneus (Bronze Cory) is usually around 4 days (96 to 100 hours) at average temperatures 23ºC to 26ºC (73ºF to 78ºF). There is one product that has proven to be good at protecting Cory eggs from fungal attack and that it API's Pimafix, this is an organic treatment and should not affect any filter bacteria.
There is another natural treatment that I have been using for a few years and that is Adler cones, these are small dried cones from the tree Alnus glutinosa, [http/www.british-trees.com/guide/alder.htm] these are fairly common in the UK and on the East coast of the USA. I normally harvest Cory eggs and put them in a 3 litre container in water from the spawning tank, plus an air stone and 2 cones. The cones release a tannin which in turn stains the surface of the eggs, this coating is what appears to protect the eggs from fungal spores by forming a natural barrier.
Hope this helps
Ian
Hope it works.
Mine didn't hatch. They do great in the hatchery. The problem is when I take them out. If I let them hatch in the bubble thing they die. If I put them in the tank to hatch they get too much fungus and don't hatch. I did have the 4 to fungus and hatch and live, but I don't know how it happened. They are the only ones of this kind that I have gotten to hatch and survive. I am trying very hard to get it right though.
Good luck!![]()
Hi drewry
I was surprised to see that your corys spawned already, but corys will do what they please.I do hope you have better luck with this batch.
I noticed that both you and ICEEGRL have been moving your eggs and then they get fungus. Eggs are very delicate and easily damaged. Could you be harming them during the moving process?
There is an optimal time for moving eggs. When they are too fresh, they are soft and squishy, and will break easily. If this happens, you may see very fine, hair-like strings on them after awhile. If too much time goes by before you move them, they will lose their stickiness and fall to the bottom of the tank or the container you are keeping them in. If this happens, the water may not circulate properly around them and they might be lost too. I find that somewhere around 8 hours after they hatch is a good time to move them.
Far better, IMHO, is to set up a spawning tank and move the adults after they have finished. Then I don't have to touch the eggs at all. I put a thin layer of gravel on the bottom of the tank so it's easy to clean out afterward, and hatch the eggs in a bare bottom tank. This isn't practical for corys that only give a few eggs at a time, but it works very well for fish like C. aeneus, that lay big batches all at once. You can then proceed to raise the fry right in that tank, at least for a while.
Hi drewry
It's good to hear your happy news! What do you plan to do now? What kind of food do you have for them?