u/Next-Wishbone2474

So today I just found out what a Cory sting feels like! I was rummaging around the back of my tank looking for dead Rainbow Shiners (different post, different story) and after feeling loads of mulm and decomposing leaves behind the hardscape, something hit me! It was pretty painful, much like a bee or hornet sting, swelled up and hurt for around 5 hours. I’m just glad my Sterbais are in another tank as apparently they have the strongest Cory venom! So watch out - Corys are uber cute but they can pack a punch!!!

So yesterday I went to Spain to 2 fish shops (I live next-door in Gibraltar and our local fish store can hardly keep up with demand, often runs out). My Betta sorority, which has been going over 25 years now, has recently lost its oldest inhabitants, after 4 and 5 years variously. I had 2 girls left and they weren’t doing well because their social structure had fallen apart over the space of 2 weeks poor fish.

First fish shop (a chain) had 2 females, both stressed and clamped fins in tiny bowls. I bought them anyway hoping I could improve their lives. You can’t keep 4 girls in a sorority (theyre like hens and need an odd number or someone will die) so I went just over the road to another shop where at least theyre keep Bettas in small tanks - I got 3 beautiful girls, one red, one blue, one both colours. By this morning the females I got from the first place had died. I have no idea why, there was no aggression (there rarely is in my way of keeping a sorority), not a mark on them - I assume the final stressor of moving them via 30 minutes in the car to a proper tank was too much. SIP my little fish.

So I have a temperate tank, with fancy goldfish, cool-tolerant Corydoras, and until yesterday a shoal of 7 beautiful Rainbow Shiners. I’m aware they’re probably the most sensitive fish in that selection.

Yesterday I visited a fish shop a few kilometres away in Spain as my LFS doesn’t stock a huge range of aquarium stuff. I bought and used Tetra Crystal Water just in that tank as it’s always cloudy, but I assume from goldfish and Corys rummaging in the sand. This morning all my Rainbow Shiners were dead. Why?

Another issue I have is I have only found 2 bodies, which means there may be another 5 fish about to start rotting and releasing ammonia. So should I leave it today, hope the Corys eat their fill, then do a massive clean out and water change tomorrow? Or should I do that tonight, though I believe peak ammonia emissions happen after 36-48 hours. I’ll never use Crystal water again for sure!