Near Fatal CO2 Overdose
On the weekend, I nearly killed off my tank because I neglected to keep an eye out on the CO2. By the time I realized things, I had loss one cardinal tetra, but the neon tetra was flopping upside down and not able to swim correctly. All my 2 bettas appeared fine although they still appeared a bit sluggish, but 1 was floating and not really moving much.
I quickly did a 40% water change, and put the fluval U2 filter in mode A which uses the air intake and aerates the tank quicker. The tetra disappeared and the next morning, I found him behind the filter, and I jiggled the filter off the glass and it swam freely! That was an amazing sight and serve me a reminder to be more mindful when dosing CO2. Just as well, my 1 betta recovered too.
It's a 8 gallon aquarium so need to watch it with a close eye to as if not overdose.
Just a lesson learn that I thought I'd share.