Brown on Caladium leaves?

My Caladiums have developed brown stains on their leaves. The whole leaf doesn't die, but the brown kind of melts away. I know they don't get too much sun, but since they are in containers I wonder if it could be caused by too much water? I only grow Candidums in round bowls and have never had this trouble before.
Pati

Can you post a picture please. If the spots look wet, it could be a bacterial problem. Plus caladiums are prone to root rot. Could well be to much water. John.

Thanks for your answer, John. I think you've nailed the problem. The spots don't look wet, more like a dry stain. The bowls sit in my shade garden surrounded by ferns and other plants that require moist soil all the time, so they get watered daily. When it gets hottter I water twice a day.

I did take some pictures, but was very disappointed. Sent my daughter to buy a digital throw-away camera which are fairly expensive, so she did me a "favor" and bought a package with two throw-aways for 7.99! Soooo, as soon as I get out and about I'll get what I need and take some pix.
Pati