New green terror agression

[SaltyPlum]

I have a 230g community tank with the fillowing:
- Pair of young motoro rays (around 15cm diameter)
- 5 red hook silver dollars (5/6 inch)
- male JD (9 inch)

The tank was going really well with no issues with the above mentioned stock. Ive always wanted a GT and from what i understand about GTs is that they are semi aggresive and can coexist in a community tank. Knowing i had plenty of room i decided on getting one.

My lfs order me in a 6 inch male GT (white saum). I orginally wanted a gold saum, however when i went in to pick it up i loved the look of it. It's been well over a week since i added my new GT and i expected him and the JD would go at it being both males. However, I noticed today the GT was nipping at my rays and chasing my silver dollars. When i walked up to the tank to inspect closer he was even trying to have a go at me through the glass, puffing up his gills at me and such. I put my finger on the glass to see what he would do and he went mental trying to bite me. I was really shocked as I would never expect this type of aggression from a GT. Ive kept in the past big doviis, jags and red terrors that never showed this much agression towards me.

I love the look of this fish and i can tell it will grow into a nice looking beast. But now im really worried about it stressing out my rays.

The tank has only been running for about 2 months now and i haven't added any decor yet, only black sand. If I add some driftwood and rocks to the tank would this help lower the GT's agression?

Any advice from members who have experience controlling agression in a community tank or suggestions on what to do would be appreciated. Pic of the white saum below.

 

[duanes]

It is quite common for a lone cichlid of any species to become hyper-dominant, if it can get away with it.
Andinoacara, are semi social in nature, and this often tempers aggression against non Andinoacara bit.
I keep a dozen Andinoacara coeruleopunctatus in a 180 with a couple tetras, a Pleco, a crawdad and an Awous goby (maybe, haven't seen it in a few weeks), and the cichlids tend to flare at each other a little, but real aggression is minimal.


if you have large enough tank (like you do) it may be best to try a shoal.

 

[SaltyPlum]

It is quite common for a lone cichlid of any species to become hyper-dominant, if it can get away with it.
Andinoacara, are semi social in nature, and this often tempers aggression against non Andinoacara bit.
I keep a dozen Andinoacara coeruleopunctatus in a 180 with a couple tetras, a Pleco, a crawdad and an Awous goby (maybe, haven't seen it in a few weeks), and the cichlids tend to flare at each other a little, but real aggression is minimal.
View attachment 1377512
View attachment 1377513
if you have large enough tank (like you do) it may be best to try a shoal.

View attachment 1377514

When you say shoal do you mean i should get more of the same breed of fish, so more GTs?

 

[duanes]

Yes, I mean a group of GTs, say 6 or 8, could be more. 1, 2, or 3, usually doesn't seem to cut it.
At the moment I have a dozen, Andinoacarain my tank.
I used to here people say they had trouble keeping Cribroheros rostrum fro killing each other, and/or being hyper aggressive. I kept a group of15 together, without a hitch.
In the photos below, they were about 7-8".

 

[adamsfishes]

Every larger solo GT I've seen has been super aggressive like this. There is currently a big beautiful one at the LFS that acts just like yours.

 

[Zanzag]

Decor would probably go a long way for the aggression.