Schooling Mono Argentus My Butt!

[WhiskeyTrouble]

So It was recomended that I get 5-6 mono argentus or one. Of course I grabbed all 6 because they are hard to find locally. They were also very small so I knew I would have some time before I had to either upgrade or split them into two tanks. They have now singled out and killed 2 so far with another on his way out. (severe skin tear on one side and nasty top fin almost torn from his body) the last 2 died this way as well. Any way I can keep them from murdering eachother? There are 2 large hiding spots in the tank which they love and lots of plants to hide behind. I dont see how I could possibly break their line of sight anymore than I already have. Im super close to just taking the last two healthy ones back and getting credit and just keeping the one.

Any help? Should I take the last 2 healthy guys back and just keep one?
If I do that then what might I find to replace them? I was thinking a scat but they get bigger than what I want. Same with brackish catfish. Way too huge. Datnoids as well. I have two archers in the tank who go together like peas and carrots.
Everything that I look up ends up reaching like 2 feet long. or 5 inches which would eventually end up eaten by the archers Im assuming.

sooooorrrrry for the long post.

 

[jcarlilesiu]

I have found mono sebaes and argentis to be touchy as far as their aggression goes.

I have successfully housed a couple together, but there are a few rules to keep in mind.

1. They must be introduced to the tank together. Putting one in first, then adding another threatens the 'terroritory' of the first making them more aggressive.
2. Make sure to get ones that are the same size. Usually, larger ones will always pick on smaller ones.
3. Be sure to provide clean safe BRACKISH water and plenty of food. When these fish aren't happy... they get mean.
4. Break up their line of site as much as possible and be sure to provide lots of long leaf types of plants. My monos always hide between large leaves and "claim" a spot in the tank. If one can view another one all the way across the tank, they for some reason think they are intruding and get aggressive.

Monos are listed as "community" but like other fish are semi-aggressive specifically to each other. I think they are listed as community since they rarely have problems with fish other than their own type. They also get large, have special demands, and take some working with to get to know their characteristics.

 

[WhiskeyTrouble]

They were all about 1 1/2'' when I introduced them. I put them all in at the same time. I got them all from the same store they were all housed together in a small 10 gal. tank. I watched them for a week before I bought them and they all seemed healthy and ate well. They established their "territories" after the first week and then one by one started picking eachother off. There are 3 that seem fine with eachother now but I have noticed that one has had a major growth spurt becoming larger than all of the rest. The battered one I have at the moment gets all of the agression, but Im afraid that when that one dies the three that seem to get along will turn on the next smallest member until there is one left.

I have not converted the tank to brackish yet because they are still very small, and they come fresh. I wanted to wait a few weeks to see how they did so that if I had to restock the tank I wouldnt have to set up an seperate acclimation tank. I was going to try to find a combination of fish that seemed to work, then convert the tank over and have that be that. I know they get large and are very active swimmers. I dont plan on keeping them in the 100 gal. forever. I planned on upgrading later when neccessary. Im running out of freshwater time, I feel they need some salt fairly soon and am just waiting to see what these monos will do next. They do not bother the archers really so i know its just towards eachother.

should I wait and see? Should I take the healthy ones back (keeping one)and try to find another solitary fish?