View Full Version : When is it too much aggression?

09-07-2015, 06:02 PM
Okay, so I had to tweak some plans for my 20 gallon community because my male betta is a little [redacted] who kills other fish. He's now off on his own in a very nice little 2.5 gallon (biggest I could find that would fit in the only spot I had left) tank on his own.

My 20 gallon has now been reassigned a sorority-community tank with 5 females (the other fish will be added later). Now, they've only been in there for 2 days, bought young, healthy females as best as I could (so dang hard to find female bettas at all every store only seems to have maybe 5 total and when you have criteria... *shudders*). Anyways, my five girls are settling in, establishing their pecking order, I haven't seen any fights (in fact I've seen them getting along just fine aside from a few mild flares and some moderate chasing, no worse than what my neon tetras do with one another) but 2 are missing mild pieces from their fins (dorsal and anal respectively). This is making me wonder when I should try removing someone. I don't know who's responsible for the missing pieces, and actually these two seem to be at the very top of the pecking order and are usually around one another so I can't help but wonder if they didn't go after one another in a quick tussle.

I also had one female who had some rough handling in transport I'm guessing, as she had a bent gill cover and seems to have trouble eating betta pellets (they seem almost too big for her mouth despite her being one of the larger individuals (all of them were close to the same size, and around or under an inch) in the tank). I'm wondering if there's something else I could feed her? I've yet to have luck getting a betta to eat even specially formulated flakes.

For the record, I am (currently) target feeding all of them to avoid anyone getting too much food or too little.

09-07-2015, 06:18 PM
How much aggression you want in the tank is up to you. IMO if the fish can't lead a normal life and you are losing fish to stress or out right deaths then you should re home the aggressor.
I feed my betta Micro pellets, freeze dried daphnia, brine and missis shrimp.

09-07-2015, 06:38 PM
I rehomed (or rather, retanked) the killing betta, but of the females (who are still new and establishing a hierarchy)I wasn't sure when I needed to step in. I have not done a sorority tank before and while I have kept several male bettas (two by some miracle in the same 45 gallon planted tank without incident by utter accident) I've never had to deal much with fin nipping. It simply hasn't been a thing in previous tanks (until my current male went after and murdered my tetras and shrimps while waiting for the 20 gallon to cycle).

I've had community tanks before, and I do know to keep an eye out for obvious aggression, but I'm not quite sure when the aggression line is too much among a species like betta who are, even in the more sociable females, guaranteed to fight at least some, especially when first introduced to tank and each other. I would rather step in and put someone in a breeder box to float for a few days than have any of my girls killed.

09-07-2015, 07:41 PM
I would just keep an eye on the females and see what is happening, most likely they are just setting a pecking order.
Is the male betta tank close to the female tank?
When you decide to reintroduce the male and females together you could try putting the male in the breeder box and slowly introduce him to the females for a couple of days then release him and monitor his behaviour towards the females.

09-07-2015, 08:16 PM
No, they are in separate rooms, and the male is NEVER going to be in with the females (I am not attempting to breed them. I simply like having pretty fish to look at and care for). They're going to have a couple small plecos and some tetra's and shrimps for company. Roughly 8 of each besides the plecos (1 clown, 1 bristlenose)

09-07-2015, 11:17 PM
I think the shrimp may not fair well. As far as aggression, its too much when fish are showing signs of stress imo. If any of them are staying in a corner or not feeding properly you definitely have a problem.

09-07-2015, 11:37 PM
They did (mostly) fine with the killer betta on the loose, plus my tank is fairly heavily planted with a lot of other hidey holes (and more coming since I need to add driftwood for the plecos). I always try to make sure there's at least 2 hiding spots (or plants) per individual fish and 4 per school if I have a schooling species. I know shrimp don't necessarily school, but I count them as a schooling species so there's 8 spots just for the shrimp alone, 5 (actually 6 but 2 always seem to be a bit stuck together floating around) "betta specific" spots for the bettas (I have no illusions that they'll be the only ones using them), soon to be 2 pieces of driftwood, and 5 decorations (one of which may be getting the shaft cuz I just don't like it with the rest of the tank and I need more room for the driftwood).

and aside from the one who just seems to be perhaps mildly crippled (I checked on her during evening feeding, her gill cover is sticking out less so she seems to be healing a bit) they all eat just fine... in fact if I didn't target feed some of them would look more like little goldfish they'd get so fat. They're already all coming up and forward when I approach the tank and I check on them once in a while as I pass the tank. So far no more ripped fins and there's not even a lot of flaring. I do just worry.

My set up is intended to be (at the moment) 8 neon tetra, 8 cherry shrimp (if I can find them, my LFS gets them rarely and I try to avoid chain stores), 8 ghost shrimp, 5 female betta and 2 pleco (1 clown, 1 brisltenose) in a tank with 4-5 bottom decorations, 2 pieces of driftwood, and every available part of the bottom covered in whatever plants I can get to survive down there (and maybe some moss balls).

and yes, I'm well aware there's a good chance I won't see the shrimp or pleco's more than once in a blue moon.

09-11-2015, 08:35 PM
I've never done a sorority tank but I have read its better to keep them in larger groups, the more there are the less aggression there will be. I know its abit late to comment but I thought I might as well:)

09-11-2015, 09:53 PM
I actually seem to be doing just fine with 4... One died, I replaced it (rearranging the tank while I did so since I had to anyways to put in my driftwood) and then that one managed to jump out through the cord slot and under the desk/stand the tank was on in the night so... I kinda give up on that. Either way, with just the 4 of them I have seen no flaring, no chasing, no fighting, and no extra pieces coming out of fins. SO... I'm assuming the four I have are going to work fine together and I am not going to try getting a fifth again unless there is obvious aggression that's resulting in stress to any one fish.

I will be adding other fish in there so the tank as a whole will be just barely under fully stocked according to aqadvisor (which I no longer trust completely as it said 3 ghost shrimps in a 5.5 gallon tank was over half stocked when according to every other bit of information I've gotten on them you can keep 5-10 per gallon.) If I see aggression I'll try adding another female (or maybe 2) in there to space it out...

11-08-2015, 08:32 AM
This is exactly what's happening in my tank :( my betta is relentless and keeps chasing my other fish, i thought it was just chasing them to make a point that he was the boss, as he seemed to not REALLY bite them. But this morning one of the fish has parts of his tail missing :( what can i do? I can't invest in ANOTHER tank, i've just spent a lot of money on this first tank. I'm thinking of adding a lot more plants to give the fish somewhere to hide?

11-18-2015, 01:50 AM
Hey dude, since all my aggression died down already and any nipped parts have healed, I can say pretty easily 1) it sounds like you added fish too soon if you JUST bought and set up your tank (cycle, then add fish) and 2) I go by a rule of thumb of having at least 1.5 hiding spots for each fish I have, that counts plants, pieces of wood, decorations, and even my filters (because my fish hide behind them often). I will say, if you need to, try 'removing' the betta for a short time with a breeders box or breeders net (cheaper, you can buy them at the store, they just clip or float on the side of the tank in the water usually) and that way he can't attack the other fish. I've found it works pretty well for getting an overly aggressive fish used to other fish... or for introducing new fish into a semi-aggressive tank (it's how I introduce things to my sorority tank, though I wouldn't really call it semi-aggressive, it's home to white-skirt tetras, female bettas, and plecos which can all get testy at times). I've also used it to separate a fish that had a temporary diet change when a female became impacted and thus I was feeding her peas while the others continued their regular diet.