That will be enough. I'm doing the same thing (filtration) on my 450. I use my Nu-Clear filters just for mechanical filtration and the trickle system keeps the water quality in check. Initially I was checking my water almost weekly and tweaking the trickle up or down as needed. Now I do a sanity check every 3 to 4 months. As the fish grow, eating more, I need to slightly adjust my trickle. I'm up to about two gallons an hour now. The plants around the house love it. I ran the trickle to a garden hose and move the hose to a different tree or bush every couple days.
how do you figure out the rate? i mean, do you really put you trickle line into a bucket for an hour an let it run or have you figured out a drip rate per minute equal a gallon rate per hour?