For Suriname Filas... its easy and best to start correctly with the same size.
I would get a group of three or four that are of very similar size best is the same.
This group in Tub 1 was originally 3 Suri Filas, I did loose one of them from an ammonia spike. All sizes were the same. No bullying at all. Very harmonious.
I do have a second group of 3 Suri Filas in another Tub, where 2 are the same size and the third much smaller. The smallest one is lightly tattered on the caudal fin, but nothing major on the body or fin spines. The other 2 similar size are doing perfect with each other. Also the 2 larger ones are growing much faster. The smaller one is getting left behind and may have to be moved out. Lesson learned.
In both cases the dominant Apex Fila in the group will grow faster and will be darker... while the others will be more silver and showing suriname spots.
If your aiming to have a group of large Filas, I would suggest to buy 3 - 4 of similar/same size and grow them out.... your gonna need some buffer since accidents can happen... Ive only kept them with TSNs, and have had very good results...
Of course the hardest part is resisting the urge to add other beautiful cats that can ruin the peace..
I did start with two allegedly Peruvian of the same size, 5". These are more or less affordable but not in quantity at $250 each usually. Suriname filas I think only come from Wesley Wong and can be $600 for small and $1500 for large 1.5'-2'. You gotta be made of money to afford a group of these
All prices before shipping.Both Peru filas came the same nice dark color with spots. Then within a day one had lightened up and is silver to this day, kinda like you state about your Suriname filas. As this thread is about TSN, not piraiba, I'll just link my piraiba thread if you wanted to see them: https://www.monsterfishkeepers.com/...yplatystoma-filamentosum.688117/#post-7755699
I think we should stay on topic in this very informative and important thread.
