Exciting stuff, but I never tried bananas, so I've got no experience.
However, the "books" say:
pH:5.5-6.5; µS: 1800-2400; possible formula: N:175ppm;P:45ppm;K:130ppm

Looks like its a heavy feeder.

Good luck and please let us know.

several years ago I saw a banana tree growing in a Raleigh, NC hydroponics store in a 32 gallon trash can converted to DWC. It was probably 8 feet tall above the lid. The guy working the counter said they were about to pull it as they had no way to change out the nutrients.
Not really answers, but food for thought while you're planning this thing.

Banana fruit is known for its particularly high levels of potassium, so they obviously need a potassium-rich formula. As they can grow in poor soils and without high water content (actually they stock water in their porous tissue for drought periods), lower N and P (P is anyway overrated from 40 upwards for almost every plant) are recommended. In temporary dry soils P is dissolved even slower as it normally is. Also, a dwarf specie doesn't need to be fed that heavily. Hence general purpose formula would probably look like this:

N=170-180
P=36
K=270
Ca=160-180
Mg=38
S=75

Trace Elements
Iron 5â¨
Manganese 3
â¨Boron 0.8â¨
Zinc 0.5â¨
Copper 0.08â¨
Molybdate 0.05

Recommended EC 1.2-1.5 in an early stage and not more than 1.8-2.0 EC until harvest. The general purpose formula could be slightly modified as in 150-160 N only, and 290-320 K to be more balanced for fruiting stage.

N=170-180
P=36
K=270
This looks very much like a fruiting (or blooming) formula, since K is about 1.5 times the N-value. It's probably better to drop that to equal N, while the plant is still maturing.

Thanks for that explanation.