What to look out for?

[matro]

I was just hoping for some tips on general pests. I have a cycling 75 with about 20-25 lbs of lr. This is my first tank and am noticing lots of stuff emminating from said lr. What is a good indication that something is bad? Is something with clear tentacles that survives the cycle bad? something with thin purple white-striped arms reaching from a crevass? I don't have a digital camera but am starting to think I may need one.
Basically, can you give description/pictures of things that if I see, I should kill.... Peacefull, aren't I?

 

[ratpack]

picture will help here:thinking:

 

[beth]

Very good, but don't forget to FEED the tank....even if you don't have fish in it. Where there is life, there is the necessity to feed it.