My grandmother has a blind Betta that spazzed out when we put him in a bigger tank. The only place he is happy is in his tiny 1/2 gallon bowl. she does daily 50% water changes on him and her house stays very warm so Im guessing his water probably stays at 68-70 degrees but i was wonderring about those flat Betta bowl heaters. Ive read some good and some bad reviews on them and just wondered if anyone here uses them and do they go in the Betta bowl under the gravel or under the Betta bowl on the outside? Any advice would be great, thanks :)