So im new to ponds. Description of my pond on profile. The setup is only several months old. I was cleaning my filter and down in the bottom with the bags of media or whatever its called i noticed what looked like little red worms and also looked like some in the next to last and the last filter. Ive had a little problem with i assume stringy algae in the water so every week or other week i clean the filter. I had just put fresh water in my bucket to wash the bags of media. I know use pond water. I have well water. Anyway it looks like red worms in with the media, i thought the heat was getting to me. Then i seen a little red worm wiggling around near the top of the bucket. Best way i can describe them is movement like a larva, red, less than .5in long only see them in the filter. I had a pic but accidently deleted it. What are these worms? Why? Should i be concerned?