It should be outside. Your plan to keep it inside then place it outside for next winter is a dangerous one and could possibly kill the tree.
You will not be able to induce dormancy keeping it inside. Dormancy is brought on by shortening daylength that Northern latitudes get with the changing seasons (yes, Fla. is subject to seasons even though you don't get extreme winters--days do get noticeably shorter). The dormancy process begins in June at the summer solstice as days begin to get shorter. The shortening daylength "tells" the plant to put its efforts into building roots and woodier growth and not into leaves. It also tells them to start storing reserves in their roots. The process can't be duplicated very well--even with artificial lighting and timers inside. You cannot "force" a plant to go dormant.
If you place it outside in the fall, expecting it to go dormant in a few weeks, it will not. If you get frosts and (heaven forbid) freezes when it is outside at your parents home next winter, the plant will simply be shocked into non-growth. If it is frozen deeply enough, the tree will be killed, since it has not built up the winter hardiness that the dormancy process initiates.
Your saving grace is that you're in Fla. and freezing presumably won't be an issue. However, since the a primary reason to keep a trident inside might be to avoid deep winter cold, why is it inside in Fla.?
You live and you learn, I guess I'll find out the hard way if it doesn't make it. I live in a apartment complex so that's the main reason why there indoors. Even if I did have a patio outside I would still have some indoors with me. I really enjoy Having them inside with me I can always glance over at them and enjoy them. I've been into bonsai for the past 10yrs off and on so I've had a few die on me, but this one will be a lot more costly if I lose it. I will try my best to keep it alive and only time will tell.
