Tip:  Always water by hand. Automatic watering systems lead to dead or dying plants. I once had a 10,000 square foot Cattleya house that had automatic watering. It was great when it worked. By the time I opened the house in the morning 3 days a week, the watering and fertilizing was done. Problems arose though when particular watering heads would become clogged. The problem was that you could not really tell until a group of plants started looking sickly. Sometimes this would be after literally months of little or no water. Even with a filter on the system, over time there is a buildup of minerals in the pipes, which occasionally would flake off and create clogs. The other thing about hand-watering is that this is the time when you get to look at ever plant. When I water is when I find other problems. Enough said.

Probably more plants are killed by under or over watering than from anything else. Some of the following hints might help you to avoid the common pitfalls.

Water quality is very important. High concentrations of minerals, high water hardness, or water with a relatively high pH can affect the uptake of nutrients, lead to mineral buildup in media, and can have other deleterious effects. Have your water tested. If at all possible, use rain water (test this for pH also, especially if you live in an urban area). If your water quality is marginal you might have to occasionally flush your plants with a slightly acidic mixture (you can find instructions on this practice elsewhere). An inexpensive RO filter is a good investment and will help to protect your valuable plants. Never use water from a water softener.

Be sure that the water is not too cold; this is especially important in the winter. Here in North Carolina I have to heat the water in the winter; the temperature of the water from the well is in the 40's and would kill the plants if applied directly to the leaves. Previously I would run a hose from the kitchen sink out to the greenhouse, adjust the water temperature until it was lukewarm, and then water my plants. My wife hated it but my plants loved it.

Water from multiple directions. Water the whole bench from one side and then again from the other side. Did you ever notice how you can stand under a tree in a rainstorm and for quite a while you won't get wet? Leaves are great at blocking the water from hitting the media and watering from a second direction will help to hit the places you missed on the first pass. Try this: Water your plants and when you are done, take some of them out of the pots. I guarantee you will find some some that are not wet all of the way through.

Use a watering wand to extend your reach. There are nice inexpensive ones (I bought a new one today that is 36" in length with 8 spray settings and a shutoff valve for $8, a good investment). These are a great tool for getting the water where you need it.

Water before you fertilize; wet roots will uptake the nutrients. With dry roots, much will run off and you will lose valuable fertilizer (called "money-water" by a friend of mine).

Water more often in the summer when it is hot and less often in the winter when the plants don't dry out as quickly. Adjust your watering scdedule to fit the weather.

Mature plants should be watered 2-3 times a week but allowed to dry between waterings (keep small seedlings a little wetter because they don't have big psuedobulbs to hold water reserves). Pot in a media that provides enough airflow through the mix that this drying will happen (see the potting media page).
Thin leaf types should not dry out, but don't allow them to stay soggy (this applies to most orchids)
Never dry but never soggy. Phals should be potted in a mix that will keep them from drying out too quickly.
Most Dendrobiums do no tlike to stay dry for long. Water and fertilize often during the growing season and less often during the winter.