How can I curb aggression within a community tank?

[Jinganni]

Hello! Fairly new to the hobby, and I was wondering if there was any way to curb aggression with community fish. My situation is a bit complicated, so let me explain:
Basically, I have a 20 gallon tank with 7(?) guppies, 3 platy, and a nerite snail. It's lightly planted because it's still fairly new, and it has 4 lava rocks (maybe a little bigger than the palm of your hand) arranged so there are hiding spots. I also plan on adding some driftwood once I have the funds.
I also have a separate 10 gallon with some plants and a betta. This was my first "real" tank, and I've had it since late last year (to make another long story short, my preteen sister bought a betta and then completely forgot about it, so I took it. I kept it until it passed, and by that point I decided that I really liked fish and wanted to continue keeping them).

When I first got my betta (a male koi plakat), I read (from various online blogs/forums/etc) that sometimes it's possible for bettas to have tankmates. I wanted to see if my betta would tolerate any tankmates, so I got a guppy and 2 nerite snails the same day I bought him to test his temperament. The nerites were fine; he nipped at them at first but quickly lost interest. But he really did not do well with the guppy; and after an hour or so I decided to remove it so my betta wouldn't kill it. I moved it to the smaller ~5 gallon with one of the nerites until I could afford something bigger so I could add more guppies.
Admittedly, it took way longer than I wanted. I got the tank and cycled it before adding more fish (and part way through the cycle I added the lone guppy once I thought it was safe so I could toss the tiny tank); and about a week or so ago I got some more guppies and a few platy to try and start a community.

As you can guess, it did not go very well. My original guppy is very aggressive and will not stop nipping at any of the newer ones. It got so bad that I had to build a "time-out" area (which consists of a clear plastic cup, lid, and two pieces of styrofoam) to make it so he couldn't hurt them anymore. I poked holes in the cup to allow water/air flow, attached styrofoam to the sides to keep the cup from completely sinking and so it can float horizontally to give him the most space to move, and I keep it around half to 2/3rds of the way full of water; I also completely empty the cup and replace the water at least twice a day so waste doesn't build up. I've tried letting him out a few times (in general and during feeding), but he is relentless and won't chill out. The other fish will approach him while he's in the cup and he tries to go after them; I thought that if they could see each other but not touch that would help them get used to each other, but I don't know if that's working.

This is obviously not a long-term solution and far from ideal, but I want to try anything and everything I can to integrate him into the community before trying to rehome him. What else can I do? Do I need taller plants or more decorations to block line of sight? Even if the line of sight is broken he'll chase them down or follow them. If I add more females, will that curb the aggression? What else can I try?

Sorry for the long post and thanks for reading. ;-; )/

 

[Sgooosh]

Hello! Fairly new to the hobby, and I was wondering if there was any way to curb aggression with community fish. My situation is a bit complicated, so let me explain:
Basically, I have a 20 gallon tank with 7(?) guppies, 3 platy, and a nerite snail. It's lightly planted because it's still fairly new, and it has 4 lava rocks (maybe a little bigger than the palm of your hand) arranged so there are hiding spots. I also plan on adding some driftwood once I have the funds.
I also have a separate 10 gallon with some plants and a betta. This was my first "real" tank, and I've had it since late last year (to make another long story short, my preteen sister bought a betta and then completely forgot about it, so I took it. I kept it until it passed, and by that point I decided that I really liked fish and wanted to continue keeping them).

When I first got my betta (a male koi plakat), I read (from various online blogs/forums/etc) that sometimes it's possible for bettas to have tankmates. I wanted to see if my betta would tolerate any tankmates, so I got a guppy and 2 nerite snails the same day I bought him to test his temperament. The nerites were fine; he nipped at them at first but quickly lost interest. But he really did not do well with the guppy; and after an hour or so I decided to remove it so my betta wouldn't kill it. I moved it to the smaller ~5 gallon with one of the nerites until I could afford something bigger so I could add more guppies.
Admittedly, it took way longer than I wanted. I got the tank and cycled it before adding more fish (and part way through the cycle I added the lone guppy once I thought it was safe so I could toss the tiny tank); and about a week or so ago I got some more guppies and a few platy to try and start a community.

As you can guess, it did not go very well. My original guppy is very aggressive and will not stop nipping at any of the newer ones. It got so bad that I had to build a "time-out" area (which consists of a clear plastic cup, lid, and two pieces of styrofoam) to make it so he couldn't hurt them anymore. I poked holes in the cup to allow water/air flow, attached styrofoam to the sides to keep the cup from completely sinking and so it can float horizontally to give him the most space to move, and I keep it around half to 2/3rds of the way full of water; I also completely empty the cup and replace the water at least twice a day so waste doesn't build up. I've tried letting him out a few times (in general and during feeding), but he is relentless and won't chill out. The other fish will approach him while he's in the cup and he tries to go after them; I thought that if they could see each other but not touch that would help them get used to each other, but I don't know if that's working.

This is obviously not a long-term solution and far from ideal, but I want to try anything and everything I can to integrate him into the community before trying to rehome him. What else can I do? Do I need taller plants or more decorations to block line of sight? Even if the line of sight is broken he'll chase them down or follow them. If I add more females, will that curb the aggression? What else can I try?

Sorry for the long post and thanks for reading. ;-; )/

dont put driftwood in a hard water tank, messes up the params (unless you want to be fancy!!!)
ya sure its a he instead of a pregnant female?

 

[Jinganni]

dont put driftwood in a hard water tank, messes up the params (unless you want to be fancy!!!)
ya sure its a he instead of a pregnant female?

Ohh gotcha, thanks for letting me know!
And I'm at least 95% sure it's a male, judging it by it's fins and coloration. I tried taking some pictures (bad ones at that) but hopefully it illustrates what I mean.

 

[Byron]

A fish with bad behaviours is not going to change--unless you kill it. So I would rehome the guppy if it is causing a problem. Breaking up the tank space rarely works because fish communicate via chemical signals (pheromones and allomones) and the message of aggression still gets across.

As for adding wood, this is unlikely to cause parameter issues, but it depends upon the existing parameters (GH, KH and pH) and the amount of wood. The more organics (wood, dried leaves, fish food/waste produced, etc) the more affect it will or may have, depending; in a tank with hard water (GH above 12 dGH) this is not going to have any adverse effect.

 

[itiwhetu]

Add more plant, in a tank with live bearers I would aim to have about 50% of the volume of the tank in live plants.

 

[Sgooosh]

Add more plant, in a tank with live bearers I would aim to have about 50% of the volume of the tank in live plants.

Yep… but keeping plants was always hard for me, only 1/4 of the species survive and 1/10 thrive…

 

[itiwhetu]

The best way to start with plants is with fast growing stemmed plants. Forget things like sword plants, Anubias, crypts etc. Start with cheap stemmed plants. Put your lights on a timer for 10 hours per day. Buy a range of fast growing stemmed plants. Then see what survives, some species will do well others won't. Once you know what of those plants survive then you can make decisions about what other plants to add.

 

[carligraceee]

Ohh gotcha, thanks for letting me know!
And I'm at least 95% sure it's a male, judging it by it's fins and coloration. I tried taking some pictures (bad ones at that) but hopefully it illustrates what I mean.

I am sorry you are going through this. I have a community tank and it gets aggressive sometimes.

What you should know about community tanks:
- The temp should not be over 80F or lower than 74F. The warmer the temp, the more aggressive a fish will be.
- When the genders are off balance, this can cause some issues. Males tend to be aggressive with territory and your guppy has been in his home longer than the others. He is protecting his space.
- I always recommend a single gender tank with livebearers because it tends to help with the aggression. All females work best.
- Plants are very important. Add floating plants with roots, tall, leafy plants, enough rocks with holes to hide in.
- Test water regularly as bad parameters can cause behavior issues.

Ways to fix your problem:
- Rehome. This is the safest and easiest option for both you and your fish. Take him to another fishkeeper's home or back to the LFS.
- Adjust the water temp to around 75F.
- Add more plants.

What are your water parameters?

Update us whenever you can and I hope I helped!

 

[Sgooosh]

The best way to start with plants is with fast growing stemmed plants. Forget things like sword plants, Anubias, crypts etc. Start with cheap stemmed plants. Put your lights on a timer for 10 hours per day. Buy a range of fast growing stemmed plants. Then see what survives, some species will do well others won't. Once you know what of those plants survive then you can make decisions about what other plants to add.

Yes i have all the 3 listed above… my bacopa
carolina thingy is growing well, rotala too, the ludwiga and another died

 

[itiwhetu]

Yes i have all the 3 listed above… my bacopa
carolina thingy is growing well, rotala too, the ludwiga and another died

There a certain plants that commercially are grown in terrestrial beds. Ludwigia is one, usually the stems will start to produce aquatic leaves after sometime. It is interesting that your Bacopa is doing well as it is not always that easy to get established for the above reason. Plants like Cabomba, Ambulia and Hygrophila polysperma are always good starters. The larger species of Hygrophila are often a little harder to get established and maintain.

 

[Sgooosh]

There a certain plants that commercially are grown in terrestrial beds. Ludwigia is one, usually the stems will start to produce aquatic leaves after sometime. It is interesting that your Bacopa is doing well as it is not always that easy to get established for the above reason. Plants like Cabomba, Ambulia and Hygrophila polysperma are always good starters. The larger species of Hygrophila are often a little harder to get established and maintain.

Coooo. My bacopa was from a pack of random stems
At my old 1g the ludwiga was growing crazy it had grown out of the watrrr so it mightve been terrestrial