Allergic reaction to fish water?

I work at wAlmart in the pet department. The fish tanks were filthy so I decided to clean them. Yesterday I cleaned them for about 4 hours, today I was cleaning them still only today it was for 5 1/2 hours. These tanks looked black they were so gross. Both arms were in & out of that water at least a hundred times. The water was foggy dirty disgusting with algae everywhere. After my shift I noticed tiny red dots down the side of my forearm. Now 5 hours later my hands are red & fevered with tiny raised fevered welt/blister looking things.. And my forearms are covered in raised red splotchy(sp) bumps. It doesn't itch, but definitely irritated. Is it an allergic reaction? Or are my arms just really irritated?