Heater Recommendation for Biocube 29

[curator]

Because I like a cool environment - and because the temperatures are dropping, I need to purchase a heater for my new Oceanic Biocube. For aesthetics, I'd like it to be as visually unobtrusive as possible.

Any advice?

Thanks

 

[blind1993]

you can hide it in the overflow part. any kind that will fit.