Domestic Violence in my Tank

[LudicrouSpeed]

BACKGROUND:
We have 1 Panda Platy, 2 Turquoise Guppies, 1 male Balloon Molly (orange) and 1 female Balloon Molly (black). We also had a male Dalmation Molly, but took him back to a LFS because he had become aggressive, picking on the Orange Male Balloon Molly.

After we go rid of the Dalmation, the Orange Molly became aggressive to the Black Female Balloon Molly, harassing, not too violent, but she wasn't being left alone. So we separated them and put the Black Molly in a breeder net.

NEW PROBLEM:
Yesterday we picked up a Yellow Female Balloon Molly, hoping that the higher Female to Male ratio would calm the male down a bit. Instead, he practically beat the yellow one to death, nipping at her and ramming her in the head. We put her in the net for safety, but we don't think she's going to make it. She's leaning now, maybe she was badly injured in the attack or was stressed by it.

When we added the yellow one, we also reintroduced the black one into the community. Now the Orange Molly has been leaving the Black Molly alone, so at least that happened.

I'm not sure what to do now though. Should I get even MORE females? Separate the male from the community for a while?

 

[LudicrouSpeed]

Yeah... she didn't make it. I think we're going to get more females, but this time put HIM in the breeder net, giving him time to acclimate to the new fish.

 

[azmodan]

Tank size? Is this a fully cycled tank?

 

[LudicrouSpeed]

10 gallon. It's cycled. 0 Ammonia / Nitrates. Aside from a recent explosion of snails it's a clean tank. A week ago I treated for fungus, and effectively got rid of growth on my black balloon molly.

 

[LudicrouSpeed]

A friend of mine told me that when he introduces new fish he also adds a new ornament and moves everything in the tank around. The fish will then think they're in a new place, sort of, and pick new territories, making them less aggressive to the new fish. Does anyone else do this? Does this trick work?

 

[azmodan]

It does often work. 10g is too small for mollies though, as a 30 inch footprint is usually recommended for them. Mollies will sometimes show aggression when they don't have enough space, and also when the m/f ratio is not good.

Also, did you mean zero nitrites? It's unusual for fully cycled tanks to have a nitrate reading of zero unless the tank is very heavily planted.

 

[LudicrouSpeed]

Yup, 0 Nitrates. Nitrites around 30 ppm. It's not heavily planted, but I do have a nice full bunch of Anarcharis in there.

I know 10g is too small for the Mollies (now that I already have them, not before) and supposedly 10g is harder to maintain due to it's small size... but I'm pretty proud that I've managed to keep the water quality good (with help from people here on AA).

I am planning on re-homing them in a 50g but have been holding off on investing in the tank until after I move, since I've got a cross-state move coming up in a few months.

Thanks for the advice.

 

[azmodan]

You'll want to do some immediate water changes to get your nitrites as close as possible to 0. With fish in the tank you should always be striving for ammonia and nitrites at zero and nitrates >20.

 

[LudicrouSpeed]

Agh... I had it backward. I forgot my mnemonics:NirtrAtes are okAy. My Nitrites are the ones at 0, my Nitrates are 30 ppm... well only 10ppm, now that I check my log.

I added a new ornament and moved everything around. It worked, I think. My Orange Molly seemed to play fine with the new fish at first... but now he seems tired and sullen. Doing alot of sitting. Everyone else is just fine and full of energy.

I've seen him do this before, back when he was stressed from getting picked on by the Dalmatian. I'm worried that I'm going to lose him from the overall stress of the tank changes, or perhaps he's overcome with remorse from killing that poor yellow molly... although I doubt it.