Unsure what type of algae???

Keep and eye out and see of they move. They do look like flatworms to me as well. If so you can manually remove as many as possible by siphoning them out. Take a piece of rigid air tubing and attach standard airling tubing to it with a filter sock on the other end and siphon out as many as possible and then treat with flatworm exit (following directions on bottle). That is the best way if they are in fact flatworms. Here is a link to help...

Melevsreef.com - Flatworms | How to eliminate them!

 

Thanks... I guess they were flatworms.. I did a water change and aimed the powerhead at them and most let go so I directed them to the overflow pipe. I then changed my filter fiber in the sump after about 20 min. It was full of crap. --- Also I noticed after doing the water change, there appeared to be a bunch (200) whitish/clear organisms attached to the side of the sump. (like fuzz) Are these problems related... Sorry for the long post..

 

Probably not related to the flatworms. Most likely what's commonly referred to as "pineapple sponges" but w/o a picture, it's impossible to be sure.

 

I am starting to get spots on the acrylic that are the color of the flatworms but appear to be coraline b/c my magnet cleaner has a hard time getting it off the back. Is this coraline or some other potential disaster that will wipe out my tank?

 

Sounds like diatoms. Perfectly normal.