One possible problem is that if your saturation levels have reached a number that is high,say 40 Parts, and you do the %10 you are only removing 4 of the 40 so I usually recomend about %25-%30 as long as the water parameters of the new salt water and tank water are similar enough.This way the added waste products of the current life forms is diluted enough until the tank balance can re establish. I and many other reef tank hobbyists do not employ the use of canister filters as they tend to trap particles and then not get rinsed out,this causes even more nitrates. If I was going to run a canister I would make sure to clean the floss out frequently any ways as it is the excessive build up of organics that is broken down by the aerobic bacteria that leads to some nitrate issues. If you can simply keep the particles from breaking down in the system in the first place ,via regular cleaning of the pre filter sponges or carbon bags,you will be ahead of the game. If you are set on using the canister I would get some live rock rubble to put into a couple of those trays to try and combat the aerobic bacterias reactions.