Congrats, I hope this will mean a better experience for the fish keepers in your area. I would add a bit of info to the compatibility guide on the cards. An angel card should warn about how they can eat very small fish. A tiger barb card should caution about keeping them with slower moving peaceful fish, etc. For each size of tank you sell, it might be a good idea to post a typical stocking list or even 2 or 3 of them so newbies can avoid some of the more common compatibility errors. It would also help them avoid overstocking right out of the gate.
A thing that can be hard for a new hobbyist is to get set up and cycled. Maybe you could offer some jump start media for new tank setups, something like go set this tank up with dechlorinated water and come back with a coupon you give them to get a sample of bacteria from a store filter. I am sure any store filter will have huge bacteria populations the way they tend to overstock sale tanks.
Something that can be hard to find for a fishless cycle is suitable ammonia. It might be something you could carry along with a card explaining how it is used.
A thing that can be hard for a new hobbyist is to get set up and cycled. Maybe you could offer some jump start media for new tank setups, something like go set this tank up with dechlorinated water and come back with a coupon you give them to get a sample of bacteria from a store filter. I am sure any store filter will have huge bacteria populations the way they tend to overstock sale tanks.
Something that can be hard to find for a fishless cycle is suitable ammonia. It might be something you could carry along with a card explaining how it is used.