Yellowing leaves on my Dendrobium

[denlover]

This is my first Den so I am a complete novice in caring for it. The leaves
are turning yellow, so far I have lost one leaf on this previously robust and healthy plant. I notice that two more are turning yellow. I bought it from a local nursery just as it began spiking and at first it looked like it was thriving. The buds are growing albeit slowly. I bought it in September when the spikes just appeared. I have it on a western window sill with two 40w fluorescent bulbs that are on for about 8 hours a day. It is in a fine bark medium and I water when the bark is dry (between 10 - 14 days).

I am worried about the yellow leaves. Should I be watering more frequently? Is it getting enough light? It is such a beautiful plant and I don't want it to perish. I sprits the buds once a day and I have a cool mis humidifier running all day. The daytime temperature is around 70 and nighttime is about 60.

Also, I am guessing that this is a Phal Dendrobium but I am not sure. Any advice on caring for this plant would be greatly appreciated.

[Leafmite]

Unless it is actively growing, I wouldn't water it until it completely dries out. I have mine in large lava rock and plastic net pots and only water once a week. When you do water, give it a good soak for a few minutes. Your temps seem fine. I hope someone can help you. Good luck, Leafmite

[exotic_plant]

I let Dendrobium phalaenopsis type to dry out few days between watering. They are very sensitive to water in winter. It is better to let them dry even for 5-6 days than to water them often.

[exotic_plant]

One more: Dendrobium phalaenopsys type, as many other dendrobium's, flower in dry season, so it's often normal to loose few leaves. This also mean that orchid need less water then in growing season.

[syndywindy]

About 1/4 of my orchid collection is made up of dens,mostly species, but I do have a few phal type dens. I grow mine a bit differently than what the others have mentioned and have had great success. mine are quite large and are in bloom right now. Phal type dens typically don't require a winters rest, so I don't reduce my watering of them in winter. When they were outdoors for the summer, they got watered daily. Now that they are indoors because the air is drier and the heat is on, I am watering them every 3 days. I don't let mine dry out comepletely either. They are growing in a medium bark and I fertilize them monthly. They get catt like light also. They will drop a leaf here and there, so as long as the roots look good, I think you will be ok. Here are a couple pictures of mine that are in bloom now. The purple one has 3 spikes in bloom.

[denlover]

Thanks for your response guys. When is the active growing period? Based on the pictures I have provided would you say that this is in the active growing period? I have lost two more leaves since my last post. Looks like the buds are getting bigger but not fast enough. Should I use a bloom booster or should I just fertilize?