My 3 new Amazons.

[izatop]

So i went out and got my 3 new amazon puffers today. put them in the tank where i had my 7'' pleco. also, because i am an idiot, i thought that as long as the puffers are young and small, if i put a few tetras in there (they are the same size) they would not attack them until they get older (i was planning on removing them in a couple of months). definitely the dumbest thing i have ever done. they seemed to be doing good together, and i was just showing my mom the cute little buggers, as one of them decided its time for food. bit the rear half of a cardinal tetra clear off. as i was scrambling to save the others, he got another one. no chase whatsoever, one bite, CLEAN off. you wouldn't be able to tell this wasn't done with a knife. i always knew they were violent but wow. now i feel terrible. i was expecting them to start pecking at each other, but they seem friendly. still, i can barely move away from the tank.
i have read about tank decor for puffers, and i know i need to break their lines of sight and make sure they have a lot to explore. i have about 8 plants in that tank (artificial, different sizes). i have 2 different hideout things (with a few holes in each, so they can have variety) and air bubbles coming out of the gravel. nevertheless, each of them seems to be more interested in their own reflections in the glass then the pleco, plants, hideouts, bubbles, or even the other puffers. one of them is starting to explore a bit, but that's it.

is this normal for the first day in a new tank?
will they stop doing this after a while or should i add more plants and hideouts?

(i have only put them in an hour ago)

[edmlfc1]

Once you take the tetra's out the pleco will be their next meal.

[Pufferpunk]

They sure are acting like puffers!

[izatop]

well, they are less than an inch and the pleco is 7. he probably weighs about 50 times as much as each of them. do you really think that they will go after him? i took out the tetras immediately, and they don't seem to be going after the pleco yet, but i am wondering how much time i have. do you think i have a couple of months to find him a good home or should i sell him to the LFS immediately?
also, no one said anything about the glass bumping thing. i just came back home, and they are not doing it as much anymore. they seem to be exploring, and they will already come look at me with their big cute eyes whenever i get close to the tank, but i am still not sure...

[ryverrat]

when I had only a single one, it took out 2 plecos over 2x it's size overnight. Took the fins off them first then started picking at the bodies. Plecos don't move much so they are an easy target for a hungry puffer.

[marksrush]

I've heard of them just plucking out the pleco's eyes, too, which would be horrible.

[izatop]

update:
The puffers seem to have settled into their new home. almost no more glass pecking. i tried to feed them bloodworm today, they did not eat much but they ate.
one of them seems to have a weird problem. i guess you could describe it as his tail fin being closed... sometimes he opens it up fully, and then he looks like the other 2 puffers, but most of the time it is bunched up into a straight shape instead of the normal triangular one. he also seems to spend most of the day in one corner of the tank. i do not know what this means. is the tail thing something that happens often?

[edmlfc1]

The tail thing is normal. Mine don't flare their tail that often but it's beatuiful when they do. The staying in the corner is not normal. It may be getting picked on by the other puffers.