hm? oh,2 feet .I thought it was at least 3-4feet.. Well in that case plants or without plants is optional.About water cycling with plant is easier than water cycling without plant.Because usually the fish waste and additional waste food are absorb and convert into nitrate which is used by this plants.Why need to cycle water is mainly because to remove the amount of nitrate in the water.But now this plants use it up as fertilizer. Regarding the canister filter, i am not sure about using canister filter in a 2 feet tank, but seems it would be a bit powerful waterflow rate for guppies to stay in there.Not much pple keep guppies in 2 feet above tanks. Usually pple keep them in mutiples of 1 and 1/2 inch tanks,using sponge filters or undergravel filters.I do have another suggestion for filters, something different then sponge filters and undergravel suggestion,but the guide is abit long and it is in chinese.The guide is done by me so feel free to ask anything u dont understand.

http://myjavagame.net/guppy/viewthre...hlight=&page=2