I snuck a few peaks at that PAR lighting sticky while my kiddo played.
A few peaks? lol. You're a much brighter person than I am. I had to read it several times before it sank in. I felt like a first grader being asked to understand the physics of a black hole.
It looks like I'm going to have to convert my hood from a t12 to a t8 or maybe a t5 just to get up to a low light PAR. I'm going to see what my options are for that on Friday. I'd like to keep my current hood if I can.
Upgrading your current hood would involve replacing the ballast and lamp bases. You may be better off purchasing a new or used lighting system. There are also a plethora of DYI solutions depending on your technical prowess.
Now to research fertilizers. Is it possible to get the right balance of fish and plants to not need ferts? Or are the people not using ferts getting away with it due to the substrate they started with being high in nutrients?
I'm sure in a perfect world one could design a biosphere to accomplish that. My niece has a plastic brine shrimp example but that's a far cry from a planted aquarium. Using a nutrient rich substrate such as mineralized top soil will decrease the need for nutrients in the water column initially. However, eventually nutrients have to be added whether trace elements or macros. I personally have decided to use dry fertilizers so I can add what my tank needs rather than depending on an all in one fertilizer. That's not to say that it won't work for you. You may prefer to go with a low tech setup with plants that require little light and dose with excel and a comprehensive liquid fertilizer. I've seen countless beautiful tanks that do exactly that. I just don't want you to become disgusted because your plants didn't do well. Too many people who have had aquariums pickup a few plants only to see them wither away; developing a mind set that it's too expensive or difficult to achieve what they were hoping for. In reality it does not have to be expensive nor difficult. This forum has all the knowledge necessary to realize any level you care to attain.