I need some guidance! the home we purchased came with a skippy filter pond. I noticed the water stopped running down the little waterfall, im not sure why. I checked inside and there is a lot of algae, I was trying to look for any sign of a pump maybe something that was clogged, but I couldn't. I also noticed the water level seemed lower. I need some help on this, im not sure what to do, where to look, what im looking at, nothing!