One Of My Fish Is Eating The Rest -_-

You have quite a few predators in the tank, and apart form putting some dividers in your tank to work out who is the culprit (it might be all of them) it might be difficult to tell, unless you catch one of them snacking on a tank mate.
Some of your other fish are quite small, and the loaches in particular look a lot like worms, which (from my very quick search) seems to be a favoured food of some of your larger predators.

I'm not sure at the moment. I'm hoping that the more experienced keepers will chip in with a straight forward answer, as I don't have much experience, and none with the predators that you have. I don't know if having several predators in the same tank may be making the situation worse, or if it is the mixture of predators and other fish.
Have you noticed any damage on your geophagus? If not then they may be large enough not to worry about being nibbled on.
I'll spend a bit of time rummaging around the internet for further information.

Geophagus are mentioned as suitable for housing with rope fish and spiny eels, as are larger cichlids. Generally anything medium - large that isn't too active.
Some sites also mention that the rope fish and spiny eels do well in groups (not sure about the birchir), so perhaps you could move the smaller fish to another tank and use your larger tank to increase your predators. They are going to be magnificent when fully grown. I really like the elongated shape and may have spent a little time looking at a fairly well grown specimen (not sure of exactly what) in the LFS on Friday.

Catching smaller fish can be very difficult in a large tank. Remove as much water and décor as possible and remember that you are doing it to save them from becoming a snack.

In terms of catching fish, there was a useful tip on here a while back (RichardW from recollection) about using a large green net plus a blue net - if you keep the large green net still and move the blue one to usher the fish into the green one (which they think as safer, presumably as plant-coloured), this is much easier than using one net.

The LFS advised me that one of the reasons one of my tetras may have a hole in her side is due to number of males outnumbering females and harassing them in mating rituals every morning ie best to have more females. I can't attach the thread at the mo to show you a pic as having to type this on my phone. However, this might be an additional explanation in addition to the very helpful advice already given above.

I'm unsure about the spiny eel as it's mouth is know where near big enough to matchaikovsky up with the bite took out of my siamese algae eater it lookseems more like the size of the bichirs or the reed fish mouth.... I'm no expert here...
And there has been ano there victim my vampire shrimp (armoured shrimp) was dead last night.... I know he shouldnt of been in there but I pulled out a carcass 3 weeks ago and was convinced it was him so I didn't know he was still in there but he was the second biggest thing in there the only thing bigger were the geos