That's great. Where did you get that bowl?!
Whoops - didn't see the responses on this post until now!
I got the bowl from Hobby Lobby, but the sell the exact same bowl at Michaels and other craft stores. Normally $20, but both of those stores frequently offer 40-50% off coupons for single items. I got the bowl for $10.
It's a 12" bowl, but they have it in 10" and 8" sizes I believe. 12" holds 3gallons with a little room to spare at the top (excluding substrate and plants, so I'm probably closer to 2.5g)
What filter/heater setup are you using?
I live in Florida and my house is a consistent 74 degrees all year round, so I opted to not keep a heater. My water temp has measured a consistent 73 degrees for the past 4 weeks.
I'm using a mini sponge filter in the back there. Here's a link
That's the smallest one I could find for sale, but it still seems a little big for my taste. In the future I'll probably modify these to be shorter by cutting off half the sponge and intake section.