Who Gives A Fish Forums

I've got a batch of Corydora fry in my 20-gallon tank, but they're not making it past the first week. Water params are good, 0 ammonia, 0 nitrite, 10 nitrate. Temp is 76F, sand substrate, and a sponge filter. Feeding them crushed flakes and baby brine shrimp twice a day. What am I missing?

First off, congrats on the fry! You're on the right track with the sponge filter and sand. But crushed flakes might be too big for them. Try microworms or vinegar eels instead. Also, keep the tank dimly lit, fry are skittish with bright light. How often are you doing water changes?

I had the same issue last year. Adding more hiding spots like java moss or small caves helped a ton. Fry feel safer with cover. Also, check for any tiny predators like baby shrimp or snails that might be messing with them.

flyby_1 wrote: ↑Sat Apr 19, 2025 10:13 pm First off, congrats on the fry! You're on the right track with the sponge filter and sand. But crushed flakes might be too big for them. Try microworms or vinegar eels instead. Also, keep the tank dimly lit, fry are skittish with bright light. How often are you doing water changes?

Yep, dim lighting is key. I've noticed my fry chill more when the light's low. Also, maybe cut back on water changes to once a week, too much disturbance can stress them out.

Thanks for the tips! I'll switch to microworms and add some java moss. Water changes are currently twice a week, so I'll reduce that. Appreciate the help.

I don't know much about fish, but my cat loves watching the tank. Maybe the fry are scared of the cat? Just a thought.

folixa wrote: ↑Sun Apr 20, 2025 12:20 am I don't know much about fish, but my cat loves watching the tank. Maybe the fry are scared of the cat? Just a thought.

Not likely the cat's the issue unless it's tapping the glass. Focus on water quality and food size first. Also, make sure the tank's in a low-traffic area to minimize vibrations.

Another thing to consider is the parents. Sometimes adult Corydoras will eat their own fry if they're stressed or hungry. You might wanna separate the fry into a breeder box or another tank if you haven't already.

I've heard some folks use Indian almond leaves to help with fry survival. The tannins might give them a boost. Anyone tried that with Corydoras?

slowpoke wrote: ↑Sun Apr 20, 2025 2:53 am I've heard some folks use Indian almond leaves to help with fry survival. The tannins might give them a boost. Anyone tried that with Corydoras?

Yep, tannins can help mimic their natural environment and have antibacterial properties. Just don't overdo it, too much can lower the pH more than you'd want. Start with one leaf per 10 gallons and see how it goes.