Skimmer Problems

[user129]

I got my skimmer about a month ago new its a Eshopps S-120 its was working great for the last month but i had a problem with purple algae so I used Chemiclean aquarium treatment I turned off my skimmer like the directions said and did a water change when it said then after a week and a half i tryed to turn it back on only to find it would buble over to fast and fill the cup I can not turn it down any lower.

Can some one tell me what I should do/try?

Thanks
Shawn