Plants, fish, Canister Filter, O2 Question
 

Hello All!
I currently have a 30gal FW tank set up with a canister filter turning over the water roughy 10 times an hour. The tank is clean and happy. I just switched over from a HOB filter. My question is this: Being that I no longer have the water agitation from the HOB filter, should I use airstones to airate the water? Additionally, I learned from some searches on this forum that if I'm using airstones to airate, I am also removing CO2 from the water. I have a lightly planted tank with fish having a ball swimming through. What is the proper compensation between bringing oxygen in to the water and still keeping enough CO2 in the water to give the plants something to thrive on?

Any help would be great, thanks!

Can aim the spraybar or return from the caister toward's the surface to create a rippling effect but it is not needed.
Most who aim the return or spraybar toward's the surface are doing so to help reduce surface scum that sometimes form's.
Cleaning the canister filter monthly will help ensure that oxygen level's in the tank are sufficient.
Dirty filter material =poor circulation,low oxygen (inside canister),poor oxygen exchange.

Thanks. I was using the water disturbance from the HOB filter return to airate, so I want to be sure I am able to still airate water properly with the canister filter. This can still happen inside the canister, or am I misreading this?

Canister pulls water which contain's oxygen into the filter and discharges clean water.
Is the surface ripple that helps with CO2/oxygen exchange.
Just aim the return slightly upwards for more agitation.