Thank you for the replies! Upon reading some more info, I'm getting some conflicting info online... Some say fertilizers aren't needed for low light tanks with no co2 injection, others say fertilizers are always needed. I would like to fertilize because I want to give them all the help they can get...
While I'm by no means an expert on planted tanks, it is my understanding that providing for the needs of the plants in ANY aquarium, whether low tech or high tech, is basically a matter of amount and the balance between those amounts. Low tech is simply providing nutrients, light and CO2 on a smaller (or "slower") scale than a fast growing high tech setup, and the primary difference begins with the availability of Carbon (CO2). By increasing the CO2 in a high tech tank, you are increasing the ability of the plants to utilize the other components of growth (light and ferts). The plants have the exact same demands, but with a high tech system, you are simply "ramping up" the speed at which the exact same processes occur, but everything still needs to be furnished in the same proportions in relation to each other, and when one single proponent is limited or boosted, the process just slows down at best, or "crashes" at worse, depending on which element is lacking or too abundant. Some (most?) people say to make light? the limiting factor, especially in low tech tanks, since that is the one component that plants are better than algae at utilizing. So if you have enough nutrients and Carbon (added CO2 or Excel), then the stage is set for "action" when the lights come on. Algae takes longer than more advanced plants to get its photosynthesis processes going, so the plants are already out-competing it in absorbing the nutrients and Carbon. (I suppose algae can get in the game if there are enough available nutrients once it "wakes up", but that is one of the purposes of providing a "siesta"/lights off period in the middle of the day.) Of course, that's not to say that dumping a lot of ferts into the tank is a good idea, because that wouldn't be in the interest of balancing them with the amount of light they receive. Depriving plants of one or more requirements creates an imbalance that can at best stunt proper plant growth or, at worst, cause serious algae problems. Many people say the best way to start a new planted tank is to start low and increase lighting gradually. Remember, plants are still a little shocked after replanting, so they need a little time to settle in before they are up to par and ready to grow again. (Kind of like people eating small amounts at first after a bad stomach virus or other illness.)
Like I said, I'm no expert, but this seems to be the basics according to what I've read here; I'm sure someone will correct me if I'm wrong, and I wouldn't mind at all, since that would assist in my own understanding and success in this hobby.