Raising fry and deaths

[Karen B.]

Greetings 

My false julii corydoras are breeding like rabbits. At first I tried collecting the eggs, having them hatched, raising the fry but my success rate wasn’t that high and I do not really want to breed them. So now I just let things happen in the aquarium - some eggs hatch, others get eaten, some little fry are hunted down by my honey gourami, etc. That’s all fine by me.

But today I found a few weeks old baby dead, and that’s bothering me. Is it a common thing happening/natural occurrence that some even when they reach a couple of weeks (so no longer prey for anything in the aquarium, free swimming, eating with everyone) will randomly pass away or is it due to a mistake I may have made?

That’s what bothers me the most in this hobby. Rarely having a clear answer and then feeling really bad and being unable to correct a mistake I may have made.

It’s a community tank (1 honey gourami, 8 chili rasbora, 7 adults cory, 8 babies - letting them grow then I will give them away -, and up to 5 oto - I never see them, so not sure of the number anymore - and 4 nerite snails.

20 gallons high, planted, HOB aqueon quietflow 30 and an aquarium coop medium sponge filter. temps at 75.5, pH about 6.6 and kh at 0 - I did buy the kh buffer to raise it. Will use at my next WC this weekend. Gh is at 300 (on the aquarium coop test strip), no chlorine/ammonia or nitrite. For the past many many weeks I was surfing on 0-10 ppm nitrate. So I was only doing very small WC, no gravel vacuum because I had bad experience sucking up some fries, and only topping the evaporated water. I did that last time monday and added some easy green.

To my surprise right now my nitrate is at 50ppm. Can it explain the death of my baby cory? Should I hurry up and do a WC right now or some of the nitrate might be because of the easy green? I also add daily 2ml dose of excel because of my black beard algea… I spot treat, could I have accidentally spayed it on the baby?

I also added some activated carbon for 2 day (the one that is in the cartridge sold with the filter) because I wasn’t sure if I accidentally put my hand in the aquarium while having some residue of lysol wipes on my hands (they were washed but were still smelling the product.

 

[Casual aquatics]

If adding the buffer is the only thing you done differently  maybe it was a bit too much ? I mean I known corys to like 69/79 so temp don't seem dramatic  I'm sorry to hear this friend 

[PineSong]

I am sorry that happened and I know how frustrating it is not to know why it did. If the other babies seem okay, perhaps that one fry was weak or troubled by a health problem that isn't due to water conditions. Mysterious deaths are the hardest part of this hobby.

I am not expert at diagnosing water problems so I will hope others chime in about that if there are any. I can tell you put a lot of care into your tank and I am sure your fish are lucky to be there.

[Guppysnail]

I’m sorry this is happening.  Fry often pass because of internal issues or inability to learn to locate food quickly enough or just weak fry.  I had 2 BN pleco fry pass recently.  I was worried because I could see no food in the tummies like the other 80-100 BN fry but I watched them on algae wafers looked like they were eating but still empty tummies then they passed.  It happens with all fish fry. It could have been something in the tank or something you introduced or just weak fry. 

[Karen B.]

On 9/23/2021 at 9:43 PM, Guppysnail said:

I’m sorry this is happening.  Fry often pass because of internal issues or inability to learn to locate food quickly enough or just weak fry.  I had 2 BN pleco fry pass recently.  I was worried because I could see no food in the tummies like the other 80-100 BN fry but I watched them on algae wafers looked like they were eating but still empty tummies then they passed.  It happens with all fish fry. It could have been something in the tank or something you introduced or just weak fry. 

Thank you. Makes me feel a tiny bit better. I love my little fry so much 🥰