I keep my Max. teniufolia in a south western window. it is in a plastic net pot with NZ Sphag. The room it is in varies between 65-70F in the day and 50-55F at night. I water less in the winter but I never let it stay dry for extended periods of time. So I water when the sphag dries. You may want to continue with your watering schedule, especially since yours is mounted. I would suggest taking a break from the fertilizer until your see green root tips again. These indicate that the plant is actively growing. When the roots are damaged or when a plant is not actively growing, they can not take up fertilizer as well. So the fertilizer can harm the plants. Sometimes pseudobulbs can get so shriveled that they can't plump back up again. So you may not see improvement that way. Continue to pay attention to the roots. They will tell you if the plant is getting enough water. I would not bother trimming the roots for now. I would do all that in the spring.

1. For the average, non-commercial / non-expert grower, watering your orchids before you fertilize is an excellent idea, and while it's not a vital piece of care for your plants, it's something you should strive to do. And yes, water heavily and thoroughly immediately before feeding. Run plenty of water through the pot, so that several volumes of water have run out through the drainage holes. Give the mix and the roots plenty of time to get soaked and absorb the moisture. Then feed. The justification? Well, orchid roots are very sensitive to environmental conditions in general, and they are especially sensitive to salts and minerals (resulting from fertilizer) that tend to build up in your pots over time. As richardol stated, orchids just aren't heavy feeders in comparison to many other plants, and even though you are advised to feed at 1/4 to 1/2 strength of whatever the fertilizer directions say, your plant is still not going to be able to absorb all of the food. So, it will build up and could threaten your orchid. Watering heavily and thoroughly before fertilizing helps to flush out any salts remaining in the pot. And, it can help act as a bit of a buffer if you happen to mix up a batch of fertilizer that's a bit too strong, since whatever you add to the pot will now be further diluted. Plus, I have heard that pre-soaked roots are better at absorbing fertilizer. 2. Here's how I fertilize (most) of my orchids. I think this will work well for the three types you mentioned. Mix the fertilizer at 1/4 strength and use it for 3 out of 4 waterings. It's called feeding weakly weekly. Use the diluted fertilizer just as you would water...pour it in the pot, using enough that the water starts to pour out the bottom of the pot. Let it drain completely, then sit in a saucer. I wouldn't allow it to soak in, but so long as you don't leave the fertilizer (or water) sitting in the saucer for days on end, it probably won't be a problem. Anyway, like I said, feed in this manner for 3 weeks/waterings, then on the fourth occasion, use only water, no food to help flush out any excess fertilizer that may have accumulated over the last three weeks. 3. For the plants you have, and most orchids in general, getting the food to the roots is most important, so definitely make sure you are fertilizing the roots. Plants can and do absorb nutrients directly through their leaves, but it is not usually a very effective means of fertilizing them. However, most orchids are prone to rot and infections resulting from water standing on their leaves for prolonged periods. So, when you consider the benefits versus the potential risks of spraying the leaves with fertilizer, I'd say general consensus is to avoid the practice. Most likely it won't kill your plants, but it's just not worth the risk. (taking a deep breath, sorry for the long post, I tend to be wordy) So, for your plants specifically... The phal: Feed the phal year round, very weakly as they are definitely not big feeders and are especially sensitive to salts in the mix. Avoid getting water or fertilizer in the leaf crevices (and crown), and if you do, tip the plant over and let it all drip off. Phals are prone to crown rot. The vanda: Will most likely take a short winter break in growth, even in Florida, especially if you aren't growing it in a greenhouse or under lights. So, if you notice that it's not in active growth, don't fertilize it, because it won't be feeding at that time anyway. With the vanda, you'll probably want to mix up the fertilizer in a bowl or small bucket, dip the plant down in to the liquid, let it set in there for atleast 10-15 minutes, pull it out and allow it to drip dry. You could also just hold it over a bucket and pour fertilizer over the roots, but vandas are a little tricky due to their propensity to develop aerial roots all along the stem, not just at the base. The dend: I don't know anything about your dendrobium, but again, apply fertilizer to the roots, don't worry about applying it to the leaves. If there are no new growths forming/maturing, then there's no need to feed. Basically limit your fertilizing so that you're only feeding when the plant is actively growing.

Caleb, here is Cymbidium Heaven as are some parts of California. I have nil Cymbidiums, but I know that the Cymbidiums Fanciers feed their Cymbidiums heavily (every watering) during late spring and summer hence the weaker than normal recommended application rate. Heading into Autumn, so it might be time for you to taper off the fertiliser a bit and use a fertiliser with a lower Nitrogen number. See if you can find some detailed Cymbidium culture Notes written for over there. Cymbidium notes (Southern Hemisphere)

With regards to fertilizing orchids, my impression is that success is measured more with what you don’t see, than what you do. So a picture that represents proper feeding of an orchid would be far less convincing and instructive than a picture of an orchid that has been over-fed. The variety of approaches that have been employed by various orchid-growers and touted by experts is mind-boggling. But the common thread among the cognoscenti seems to err towards “gently.” In the several decades that I’ve been growing orchids (much of which has been spent with no firm concept of what orchids actually need to support their growth) there seems to have been only one major “breakthrough” which has soared above most other approaches, and which has lasted in its renown to this day. That of course would be the MSU approach of utilizing relatively low phosphorus in its overall balance, together with employing mostly nitrate-sourced nitrogen and avoiding Urea nitrogen altogether. The other guiding concept in fertilizing would be summarized by the recommendation that a steady, consistent and relatively weak fertilizing regime is more supportive to orchids than strong periodic fertilizing. There are several approaches to this process, according to how scientifically-minded one happens to be. One would be to determine optimal PPM nitrogen over a prescribed period of time based on the type of water you happen to be using. The other, simpler approach (after ensuring that your water source is acceptably conducive to orchid-growing to begin with) is to feed weakly weekly at ¼ strength of the monthly recommendation, assuming a 20-20-20 or equivalent formula. Or using that same strength as a constant feed with periodic flushing, depending on genus and its tolerance to added “salts.” For example, I don’t hesitate to constant feed my cattleyas and phalaenopsis with a monthly flushing. But I wouldn’t feed my paphs with that strength more frequently than once a week, so at least one, of not two plain water applications fall between feeding. In addition, good general feeding practice frequently advises pre-watering before applying fertilizer to buffer sensitive roots. Given the application of a ¼ strength solution I feel this is less important for some genera that others. Finally, as some readily available fertilizers are balanced for acid-loving plants, it would be inadvisable to assume that any fertilizer that happens to be on hand would be helpful to orchids. The below link accesses an article on MSU fertilizing and a table that sets out two formulas. It is important to remember that orchids do most of what they do by virture of the light and supportive moisture that they receive. The picture below represents an overfertilized, and arguably over-lit paph from an overly-eager grower, i.e., me. MSU Fertilizer Formulas