Ok, hi , how are you all doing? Currently its getting closer and closer to winter time in NYC and these past 2 days my water has been dipping down to the low 70's degrees. I need a suggestion for a heater, maybe some heaters you had personal experience or some heaters that you might think are good. I'm not thinking about spending more then 30$ on a heater.
I also have a 20L tank, 2 RES about 2inches, and a fluval 205 if that helps.
So far I've been looking at this one
[admin edit -- linked removed. please post direct links, NOT REFERRAL LINKS.]
Please suggest which one to get for my tank too because i see that some heaters have different wattage.

