To heat or not to heat...

[dexsting]

I have a 20gallon aquarium which actually not all the way full (I like the lower water line and "waterfall" effect from the filter) It's in my office which stays a stable 68-72 F all the time. I was going to get fish, but ended up being an HR issue so now I just have a planted tank.

I've got a Banana plant, 2 moss balls, Dwarf Hairgrass, Water Sprite, Christmas moss, Java moss, Dwarf Sagittaria, and the plant I don't know its name, but I think is Anubias.
I also have 4 ghost shrimp and 1 nerite snail.

Do I need a heater? The plants/shrimp/snail seem to be doing ok, but it's only been a couple weeks. If so; do you recommend Aqueon 50 or 100W heaters? What temp do you think would be ideal for my set-up?

Thanks!

 

[Byron]

I would not bother with a heater. Plants obviously cannot get too cold, but unlike fish there is little effect within reason. Heat is more detrimental than cooler temperatures, generally. Above 60F is not going to be an issue.