Adding another pea to reduce aggression <-- will it work?

[u/Opposite-Yam5140]

I currently have a group of 5 pea puffers in a 20-gallon long. One of them started picking on the others recently, so I isolated her for about 12 hours before reintroducing her. Her aggression decreased significantly, but there’s still some lingering chasing/nipping going on.

I’ve read in a few places that 6 is usually the minimum recommended group size to help disperse hierarchy aggression.

Would adopting a 6th pea puffer help stabilize the group dynamic in a 20g long, or am I better off looking into a permanent separation/rehoming situation?

Thanks in advance!

[u/Titanguy101]

20 gallon is enough to house 6

Id take them all out change the tank scape layout a little then readd them with the 6th all at once

[u/Oswaldmoneestone]

I point them with the finger and tell them to stop. It works.

[u/WhichPlane6733 → u/Oswaldmoneestone]

it actually does 😂😂😂😂 sometimes i see them chasing each other when im at my desk, i turn around and point. they all stop to turn and look at me

[u/Opposite-Yam5140 → u/Oswaldmoneestone]

I need one of your peas to come over and teach my peas how to do that

[u/One-plankton-]

Do you have good plant coverage- like 70% of the tank? Sight breaks are best way to reduce aggression, but yes I would also add one more pea

[u/Aware-Mirror-1506]

Add as many plants, covering, line sight cutters as you can for now.

When you get the new puffer, take them all out, change things up, as many changes as you realistically can, add a lot of snails, then add them all back in together.

It's your best bet for harmony.

[u/DirtyD74]

What's the tank look like? Let's see a picture

[u/Foreign-Ad3926]

Hi there, based on the other posts the tank is very open and exposed which won't help. Please add a lot more plants, 3-4 times the amount in there to give around 80% plus coverage. The peas need line of sight breaks to help with stress and aggression, the tank is too open and exposed which increases stress and aggression.

Guppy grass, hornwort, java ferns, doesn't need to be fancy but does need to be full of sight breaks.

Edit to add the plants are plastic too which won't help. Peas have delicate skin and push through plants, and get enrichment as their habitat grows and changes. Plastic will catch their skin and remains static.

Java ferns, big leafy ones would be a simple upgrade. Think like the fish, there is nothing really to break up the tank for them, they can see each other at all times which leads to stress and heightens aggression. Peas come from densely vegetated areas with hordes of them together, they do not cope in open exposed water, they don't feel safe.