Your 45 G
Hello Brent...
If you're using standard florescent, T8 or T12, 6500K bulbs, then 1.5 to 2 watts per gallon of tank volume should be sufficient to grow most aquarium plants without the need for high end fertilizers or systems.
I have a similar tank (see attached pic), with a bit lower lighting and dose API's Leaf Zone and add the CO2 Booster once a week when I do my water changes. The plants grow fine.
For this tank, the lights are a timer for 12 hours on and 12 off. I keep feeding to a minimum, just twice weekly and just a bit. The floating Waterweed and Pennywort use all the extra nutrients in the water, so there's nothing for the algae.
B