I'm going to look into the biopellets, thanks for info! I heard filter canisters are bad, are they? You think having those 4 triggers will be a lot? I do have a foxface but idk yet if I'm keeping him or selling the guy
Four triggers is a lot of bioload for 100 gallons, but it's something you can overcome with good filtration. A canister won't do that for you. You'll need good biological filtration (lots of live rock, carbon dosing, and a big skimmer). These guys eat a lot and they are messy. They like to eat food and spit it out and eat it again. My Picasso likes to get a mouth full of nori and then spit it straight into the overflow. If he can't handle it, he's not letting the other fish eat it.
Bioload is the easy part. As everyone has mentioned, the aggression is the real issue. I think four triggers in a 100 is just irresponsible. I've had my Picasso for twelve years and I've had my niger for about six. When I added the niger, the Picasso was not welcoming at all. The niger was a little smaller and had to hide in the a rock for a few weeks. Any time he poked his head out, the Picasso would go straight for him. I had to squirt food into the rock to keep the niger from starving. After about a month, the Picasso let up and the niger was able to come out. Six years later, the niger is twice as big as the Picasso. All is good. Now imagine this with two more triggers in the mix. It would not have worked out. I understand your desire for a bunch of triggers. They're really cool fish. I really want to get another one for my 220 gallon tank, but I know better. Good luck in whatever you choose to do, but if I were you, I'd listen to the advice you've gotten here.
