While it is nice to see your cousin (csn?) sharing an interest in the planted aquarium hobby, if you are going to be deployed for half a year at a time, then perhaps an aquarium that requires fertilization maintenance may not be for you.
Why not consider a lower light/lower maintenance aquarium?
I would advise against an all-in-one mix since every aquarium is different (different plants, parameters, etc), and there is no way an all-in-one mix could be appropriate for these different aquariums.
i meant can. the tank is my daughters so its easier for me to buy a pre mix and show her how to start dosing that instead off each fert separete. and just because i deploy doesnt mean my kids cant have a really nice tank.