Hi Ady, Tubeworms are easy to keep provided u don't keep fishes that nip on them. The 5 in 1 coral food is good, will be more than enough to keep the tube worms happy.
I used to use seachem calcium as well, value for money i would say. But you have to check your calcium level with test kits to know how much calcium to dose.
Read up more in this forum, lotsa things you can find out. I learned lotsa stuff from here too!
Cheers!