My newly purchased bromeliad (an indoor variety) has gnats; the center has turned black and has a bad odor. From what I have read this may be from over watering. Can I save it and how?

 

You can not overwater bromeliads. Fungus flies are attracted to overwatered houseplants. There are household insecticide sprays available. Back off on the watering. In a previous life, as I recall, you simply mist them. You must research bromeliads. These grow underneath the vegetation of the rain forest. It would be considered to a desert plant that needs minimal water to sustain its growth and moisture requirements. However, this is a true assumption, and if further requirements are needed to the attention to the bromeliad, you should inquire on your online searches or with your local Cooperative Extension Agent or local nurseries for moisture requirements and insect control.

 

I have a bromeliad and I water as soon as the top of the soil is dry. I let the water run through the soil and dump what is left in the saucer. You should find this helpful.
http://www.bromes.com/care.htm

Fungal gnats breed in moist soil. Here's some organic ways of dealing with them.
http://www.extension.umn.edu/project...ngusgnats.html
http://www.ghorganics.com/page9.html#Fungus%20Gnats:

Newt