my fish tank issue

Question
This is new to me so bare with me. I have a 72gallon tank I have had it for at least 8yrs. All the fish have been in the tank no less then two yrs. I did a gravel wash and cleaned the tank left about 1/4of the water in it. A couple of days later I noticed on the lid little tiny black bugs almost look like a knat and a crystal clear worm that looks just like the water. I've never had this problem. I have notice the bug thing are eating the fish food if a piece gets stuck on the glass but the worm are just moving around. Please help

Answer
Hi Teresa,
Not sure if I can put an exact name to the bugs you are seeing. But they are very likely one of the many types of aquarium "pests" that commonly get into our aquariums and are no harm to the fish but are simply scavengers -- as you have observed. They might simply be some kind of bug that came in from the outdoors and decided to make your tank their home. Some bugs are attracted to damp buildup on the underside of the aquarium cover, where debris, algae and other matter collect. So wiping any of that off can help discourage some bugs. But as for the bugs in the water, the best thing to do is to start doing daily gravel vacuuming/washings and siphon as many bugs as possible. This will also remove their food source and eventually the population and the food source keeping the bugs thriving will be depleted that they should go away and be unlikely to return.

Best of luck and I hope this helps!
Karen~