can these fish all live together?

[TKOS]

High iron and calcium aren't an issue for fish, though plants would certainly like that.

As for the spot look up ich or ick on google and see if it looks like that. Clown loaches are very bad for brining ich into aquariums.

 

[RarestJewel]

thanks for the advice it does seen to be ick/ich and will begin treatment right away.

 

[budrecki]

the loach has one white fuzzy spot on tail fin smaller than a pencil tip. what is this and what do I do?

Could be ich, could be fungus. ICH is not normally "fuzzy", fungus is. Most likey fungus, related to poor water conditoins.