tapla said:Hi, BB - the problem with fluoride is, it's accumulative in tissues. IOW, once it's there, it's there for good ..... or until the plant sheds those of its parts in which the fluoride has accumulated. Fortunately, it's not mobile in the plant. The older the leaf, the more likely it will be to have been affected by a fluoride toxicity, so the level of fluoride in your drinking water is only one factor affecting toxic reactions to the compound.
To avoid it, try to use some form of deionized water - distilled, rain water, snow melt, dehumidifier/air conditioner condensate, or best - water that's been run through a reverse osmosis filtration system, which is what I use for plants and drinking water. A small system costs about $200 and can be installed in a half hour (by you).
You have other issues that signal you're likely confusing cause and effect, i.e., transitioning a dracaena to some form of water culture is bound to be met with protest. They don't like wet feet, or, at a bare minimum, they cannot transition back and forth from a root environment that cycles between saturated and appropriately aerated. Most growers believe perlite is the king of aeration, but it's not. Soil particle size is what primarily drives water retention, so as long as you have enough compost to fill all the space between the perlite particles, the perlite does almost nothing to promote aeration, so you're likely trying to grow in a substrate with <10% air porosity, and it's going to be difficult to make that fly.
My suggestion would be to bite the bullet and repot into something that holds very little or no excess water. It is SOO much easier to grow proficiently when you're not required to fight your soil for control of your plant's vitality. If I was growing a dracaena, this is what its feet would be in: