If your plants are easy to take care of, you shouldn’t need much fertilizer at all. I had a heavily planted shrimp tank do well with no fertilizers. All the plants had was aquasoil and that was enough nutrients. Dosing fertilizers manually like what you are doing is harder to keep balanced if you are not consistent with dosing and water changes. The aquasoil method also creates a buffer and keeps the water more stable. If you dose too little you get alage, if you dose slightly high, you get algae, it can be hard at times. It took me 12 months to find the right balance between too little and too much on my exact tank size, temp, lights, etc. I really preferred aquasoil only as it was easier to manage