today i went to this LFS that has the most AMAZING fish, and was told that i can put an undergravel and join the tube with the intake of a canister filter. any comments? and has anyone tried it before?

its a possibility, but most of the people on this forum will tell you that under gravel isnt a good idea.

i personally have no problems with undergravel, ive used it before and its a great biological filtration. combined with your canister, would produce pretty happy fish.

they have problems with undergravel filters that keep the waste and decompose it under the substrate, then releasing poisonus gasses that might kill a goldfish that would overturn a stone that has some gas under it.
the idea with the undergravel+canister is that it will make a slower current than just canister, and it could be better for the plants.