I used to run a yo-yo shop for about 4 years before selling my stake in it!
I have a question regarding filters...I unplugged my filter, cleaned it out, plugged it back in...but no flow. What gives? The thing is on as it spewed out little bits of garbage, but there is no flow.
Is the impeller running? My Aquaclear always does it and it takes a light pencil prodding to unstick it. Otherwise, pouring water into it could be needed to prime it.