It is distilled water from the condenser, so it should be ok. Double check with an AC company to ask what they might clean the coils with when servicing. You may have to re route for a couple days after a cleaning.
Hope this helps.
Frank

I collect it using a pan under the drain pipe and have been doing so for the past 5 years. It is great when your in a dry spell with no rain.

Rebecca

The only problem could be when you run clorox to keep the drain clear.

Well, I have never had to run any bleach and never had a serviceman out, so that won't be a problem. Thanks for answering. It just seemed a shame not using a free source of water for such a good cause. As they say, every little bit helps.

I collect mine in a rainbarrel :) PJ

The drain of my AC runs directly into a planter and was my first choice when I wanted to set up a bog...but the drain is on the north side of the house and is in constant shade.
So the bog is being planned for the front yard.

Rather than run chemicals to clean the drains, I will occasionally take a car tire stem the size of the outlet pipe and a compressed air tank and blow air into the pipe to remove sludge/residue. The air breaks up any accumulations and it drains out within two minutes -No chemical run off that way.