Betta Fish: update: thank you all!

thank you all for the helpful advice on my previous post. since that point, i have now covered the open slits in the glass top cover with saran wrap for the time being until i can think of a permanent solution. there is still open portions for air flow to the tank as well. as for the temperature and water parameters, everything has been tested and is excellent. that strip thermometer is inconsistent with its results, so i have ordered a digital one instead. i have also gotten a new fish! who i now need help naming. i liked the name ringo, but im just not quite stuck on anything yet. he’s taken a bit to warm up to the tank and his tank mates, but he now seems to be loving it. thank you all again!