Above 75F and below 80F is best for all Anabantids.
Any tropical fish can get cold. A Betta needs to be kept at around 75F to 80F.
At or above 75F and below 80F is the correct range for Bettas. They breed at the higher limits.
Most tropical fish are normally kept between 70F and 80F but some species will die if they are kept in water below 75F. Others will die if they are kept too warm and 70F will be too hot for them to live. Bettas will die if they are kept below 65F for long periods. For them to live a healthy and normal life span, Bettas need a temperature range of 75F to 80F
if the room they are kept in is not 75f-88f then they could probably use one. If yoyu want to breed them keep them in 80f-88f
That depends upon the species of tropical fish you are keeping. Their temperature needs vary from as low as 65F for Whitecloud Mountain Minnows through 75F for Barbs, Danios and Corydoras and up to around 85F and higher for Discus. So you see there is a large temperature difference between the needs of the different species of tropical fish. Guppys need around 70F to 75F and Bettas need around 75F to 80F.
0.120degree c
If by "convict" you mean the "Convict Cichlid"(Cichlasoma nigrofasciatum) then the answer is a definite YES they are tropical. They can handle temperatures down as low as 72F for short periods of time but should normally be kept at around 75F to 80F.
It is a bit too warm. Bettas breed at around 78F to 80F. Over 80F and the nest bubbles burst too easily and often, so the fish spends more time rebuilding his nest than looking after his fry so that is just a tad too warm. Between 75F and 78F is perfect.
They will co-exist but Angel fish like their water soft, acid and around 80F and Mollys prefer their water hard, alkaline and about 75F.
Subtract 75F-32, Multiply that by 5- 43x5, and divide it by 9- 215/9. Answer-75F is 23.8C
Provided the water is around 75F to 80F and your filter is well cycled and the tank is large enough there is not much you can do. Maybe a water change could help.