Hello everybody! And happy 1st week of the new year!! Ive been having a lot of fun watching my tank grow, its moving into the 5th month now, although ive had some fatalitys involing my shrimp and the fish besides that everythings going well. Now i have some things that began growing and would like someone to help me identify what they are, first two pictures look like a worm the first pic lets out a stringy spider web like string every now and then, the second pic hasnt done anything, third pic they are all over in the sand, fourth pic looks like seaweed (is that bad weed) and behind the seaweed you can see these little white things all over the back wall and also all over the tank? What are these things and are they bad? Please help, thanks in advance!!!