Good morning NWA...
A venture like this will cost some money, because you'll need to grow a lot of plants to make up for your time and effort.
Fish would be a real benefit, because they're one of two sources for macro nutrients like calcium, phosphates, potassium, etc. the plants will need. The other being large and frequent water changes that replenish essential minerals.
The micro nutrients you can get commercially, so those aren't an issue.
Might need to rethink the "no fish" decision unless you can find a commercial source for the macros.
"Fear not my child, just change the tank water."