When is my tank ready for new fish?

[MichaelL710]

Hello fellow fish nerms, Unfortunately i woke up this morning to find out some of my fish past away in my 40 gallon breeder. I lost 8 Beckford pencil fish, 4 zebra loaches, 1 octo cat fish. I have now 3 pencil fish and 4 zebra loaches and 1 octo cat fish now. There was ammonia spike that i tested and quickly did an 75% water change. Fish seem to be doing fine but they are very skittish and they didn't eat this mooring. I am guessing its do because  i did a water change and level are stable and there is no nitrate and no ammonia now. I am afraid now that my Beckford pencil fish  and loaches don't  have big enough school numbers now that they wont eat or come out. how long do you guys think i should wait to get more of the same fish to expand their numbers, so their more comfortable. Thank for any assistances or advice. i really apricate it.   

[mynameisnobody]

How long was the aquarium cycled before introducing fish? 

[MichaelL710]

I have my tank running for over 4 years but I  did re aquascape back in June this year.

[mynameisnobody]

Got it, so BB shouldn’t be a problem. Could it be that someone died in the aquarium and went unnoticed? Too much at feeding time? How often do you do water changes and filter maintenance? What do you think caused the ammonia spike? 
These are the questions that come to mind. 

Edited 10 hours ago by mynameisnobody

[lefty o]

so something happened that killed a number of fish. i would give it a week or so just to make sure whatever it was isnt still happening.

[MichaelL710]

It could of been my oto cat fishs I have had the fish in another tank before and I think I have them for over 6 years now so it of past over night with me noticing.

I feed the fish one a day and I do a water change every week so I can be on schedule.

[MichaelL710]

I might just wait until next to see how many fish arr still holding up by then. Thank you guys for all your help I really appreciate as always.

[Tony s]

On 9/19/2024 at 11:42 AM, MichaelL710 said:

It could of been my oto cat fishs

I'm not sure there is enough body mass there to produce that much ammonia to crash a 40g tank. I'd wait it out. You may have something else going on.