You can most certainly grow banana's hydroponically. Just make sure you buy the dwarf varieties. No, you can't bonsai a banana plant. It is an herbaceous perennial and not a real tree.

Depending on provenance (area from which the genetic material of the plant originated) some (but not all, varieties) of F carica can be grown indoors under lights all winter. That said, it's not likely that a tree that does well or is from genetic material that does well in your zone will tolerate a lack of a chill period and/or the indoor stay. Just growing the plant under lights may not be enough, and certainly, humidity should be a consideration. Plants that are grown in marginal conditions may be tolerating continual decline and showing a net loss in energy reserves during the duration of exposure to the conditions. A steady decline over winter can leave the plant weakened and with little in the way of energy reserves to fight off disease and insects. Forward thinking, advance now - further along in the growth cycle, should leave us with the general feeling that an indoor stay was not nature's intent, and that nature has honed the survival mechanisms of your tree over eons through natural selection. Short answer: You can probably make it work to varying degrees depending on the tree itself and your abilities to provide cultural conditions the tree would prefer, but your tree will assuredly show a greater gain in biomass (showing that it would be stronger and grow better) if you allowed it a period of dormancy followed by quiescence (more quiet/cool rest) until danger of frost is past and you can put the tree outdoors come spring. Al

www.LedBuilder.org has links to some of the high quality and affordable LED grow light companies where you can find afforable pre-built LED grow lights that work really well. DIY kits and information to complete build your own from your own parts are also listed on that website. Some of the best complete LED grow lights are as follows. Put your lemon tree under these and they will produce lemons in the winter. Tasty LED Grow Lights, Johnson Grow Lights, Northern Grow Lights. Chilled Chilled Grow Lights If you want to build your own there are links to lots of resources, and some half-way DIY options you can purchase pre-selected kits of parts like: Growmau5 Grow Kits from Cutter Electronics Timber LED Grow Light Kits If you want to build your own from scratch, you have lots of options on what LEDs and power supplies to buy, you can grow watermelons in your living room if you wanted to. Some of the best parts around are Quantum Boards from Northern Grow Lights. Cree, Vero and Citizen COB LEDS from COBkits Chilled Grow Lights DIY kits These are all high quality options made with mostly the same high-end components that are better than regular shelf-bought grow lights. All this info is available on www.ledbuilder.org

i had the same prob in your last pic looks like a tomato plant purpled up. i think it is magnesium deficiency. or it could be a temperature prob. i added a lil cal/mag (botanicare) and aded a lil heat to my grow tent and i guess lowered my ph a lil and it cleared up so i would say one of those three changes did it. your pepper problem tho... hmmm neved had that. if you feed them all the same maybe they have the same problem. i can tell you peppers dont need much for ferts.