Black Wormy Things in Filter Media

Question
I have a 60 gallon African Cichlid tank that has been up for about 8 months. I have about 8 cichlids, a pleco, and some emerald cories. I have a penguin biowheel with carbon filter cartridges and a white poly-based mechanical filter thing inside. I also have a small powerhead on the top level with numerous airstones and a heater. pH is usually 7.5, ammonia is 0, and nitrites are 0. I change 20 once a week, or a little more if too dirty. I also have a separate tank that I breed guppies in for feeder, and feed live every 2-3 weeks using either guppies or ghost shrimp. Now on to my question. I have some algae growing on the plants (which the lazy pleco doesn't eat) so I pulled the carbon filters and added AlgaeQuel. I decided to rinse the mechanical filters and replace (which I usually don't do) since they had only been in about 2 weeks. When I took them to the sink I found these little brown worms in them. They are dark brown in color and no more than 1/2 inch long. I have been taking care of fish for years (though first at home experience with a large tank) And have done salt and freshwater care while working for pet stores, but I have never seen these critters before. I was actually quite grossed out and did pitch the filters, but is this something that I need to treat or are they harmless?

Answer
Hi Alex;

I've seen those before too and they seem to only be eating excess waste in the filter and sometimes in the gravel and under decorations. They like dark places. I've never known them to affect the fish in any way. Those types of critters can be a warning sign of excess waste though. Just be careful and cut back on food a bit if waste seems to over-collect. Once the waste is reduced the worm population should decrease. They may never go away completely, but they should reduce. Use them as a 'waste monitor'. Excess waste is quite common with cichlids and plecos in the tank anyway so just do the best you can. Even just fasting the fish one day a week would make a big difference. It's very healthy for fish to fast them. Helps keep the digestion running smoothly. ;-)

At Your Service;
Chris Robbins