I think if it's a 55 gallon/50 gallon 4ft long tank you can make your own lighting system from Homer Depot for about 40$. They sell electronic ballast etc, I'd definitely get one of those, you can use a shop light and remove the ballast(or just leave it in). Another option is using the powercompact outdoor spot lights(3x 65 w) that will run about 20-35$ ea.
There are other combo's you can come up with. If you are not that good with wiring etc, the A&H set up is easy/nice and the shop light is easy also.
More light is not neccesarily better.
As mentioned, A&H is a good place if you want a nicer DIY project and have more $ to spend.
As far as Petco/Petsmart, I believe they should be carrying SeaChem flourish and Flourish Potassium. But you can get things much cheaper on line and if you buy a 2 liter jug, that will last quite some time. Leaf zone
may also be available there.
As far as other nutrients/jargon.....well I stray
The "how" in growing plants is not particularly difficult. They need 3 things to grow , light, CO2 and nutrients.
Light is easy.
CO2 confuses folks somethimes.
Nutrients consist basically of only 4 things that you can add just like fish food.
Example, add 1/4 teaspoon of stump remover twice a week for a 20 gallon tank. No chemistry/jargon required.
You are already adding traces and there are only 3 other things you might need to add.
The idea is to make these things CHEAP. You can get everything at Home Depot or the drug store for about 15$.
Sulfur of potash-garden center-about 5$ for a 10lb lifetime supply.
Stump remover-about 4-6$ a pound, look for Grant's or Cooke's brand.
Fleet enema-at the drug store-mostly, don't worry it'll last a long time also-cost a few bucks.
Instead of feeding your fish brine and flake, you are feeding your plants 4 things etc. It does not have to be any more complicated than that except for the pruning and removal and sale of extra plants.
But don't add all that light without getting the other parts together (CO2 and nutrients).
You need all three, not just light etc.
You'll very likely have a poor experience if you ignore the other 2. You should not ignore one part because you don't like it or it confuses you. You don't have to make it complicated or discuss it at length, just add it regularly and keep up on it is all. That's all I did a long time ago. I started asking "why" later.....
Regards,
Tom Barr