Established Tank - Nematode/worms

Both of my tanks which have been running for over 6months each are both swarming with dfferent kinda of micro organisms, planaria and nematodes being the annoying ones. I have posted in the emergency section multiple times in regard to my nematode infestation, i have tried everything, not feeding the tank for a week(s), prazi pro, APPLUS anti-fluke, salt, nothing will get rid of the nematodes, the planaria comes and goes and really doesnt bother me that much, and i really have to look to find one, but the nematodes seem to be invincible and are on every bit of bio-fiber, bio-max, or beneficial bacteria areas. I have givin up trying to get rid of them and now there just everywhere. they disgust me, and all my filters have them. I just added a fluval 306 canister filter, a couple days ago, and im sure its probobly infested by now too.

What should I do!? I dont know what section to post in anymore, as none of the answers i have gotten have solved my problem or made me feel any better about it. DOES NO ONE ELSE HAVE WORMS IN THERE TANKS!?

My main question is, are established tanks supposed to have all sorts of little worms and organisms in them, helping create an eco-system, and break down debris, and give my fish a snack here and there, or should I be worried, because they will not go away no matter what I try. I REALLY NEED SOMEONE WITH EXPERIANCE ON THIS SUBJECT TO TELL ME WHAT THE #59### is going on. They don't harm my fish, but it just doesn't seem normal (as far as I know)

They look like this

Since you say the Nematodes aren't harming the fish you have the kind with a direct life cycle (which is sorta good). This means they reproduce without using a host. Since they aren't harming your fish id leave them alone. Its natural to develop Planaria and other organism's that eat the debris ect. I have had Planaria, Water Flea's, and all other sorts of little critters. Don't worry about it