First, I would recommend keeping a journal with a couple of pages for each orchid. That way you can look back and see when your orchid started growing last year, or when it bloomed. I refer back to my journal all the time and I write in it almost every day. Second, in South Florida about half my orchids are putting on new growth and new roots right now. Usually by the end of April, everything is in active growth mode. So I wouldn't worry if some orchids aren't growing yet.
In my opinion, the absolute best product for increasing root formation and growth is Maxicrop Liquid Seaweed. For me, it works like magic. In fact, I was getting so many roots on my orchids last year, that I cut back on how much I used it. Use it at 1 ounce (30 ml) per gallon, once every two weeks. You can mix it with your fertilizer or use it by itself in a separate application. It's not a fertilizer. You still need to use a fertilizer regularly. Don't worry about the fact that your water will turn black. It's actually very mild and I know at least one orchid grower who uses a much higher dose without any adverse effects. Don't use Superthrive or KLN if you start using Maxicrop. You should only use one growth stimulator. I would recommend using it in the spring and summer.