How to get fish to leave newbies alone

[cstonge72]

I purchased two new fish today: a Pygmy angel and a royal gramma. Immediately my clown and 6-line wrasse started harassing the newcomers. The angel is in the upper right corner of the tank when it gets chased, but keeps trying to go peck at rocks, etc. It even ate. The gramma however is in bad shape. It was getting savagely attacked by the wrasse to the point that I thought it had died for a minute there. I was going to scoop it out and realized that he was still alive, but very stressed. I actually have my net around it in the lower corner of the tank just so it can rest. Any tips to ease the aggression in my tank, or is it just Survival of the Fittest, and the gramma is just not gonna make it?! Thanks for any tips....:(

[Xavibear]

First, how large is your tank? Six-lines are extremely aggressive & should be the last fish added to a tank. Clowns depending on species & tank size can also be aggressive. An angel should be able to handle itself with the clown & the wrasse. Chances are there won't be many fish that you could add unless you have a large tank.

[cstonge72]

Small tank. Just 30 gals. I've had the clown and the wrasse for a while. I have a pajama cardinal too. I just lost a couple fish so I wanted to add a couple more.... The 6line is still a juvenile. Thought he'd be fine.

[B.BASH]

Tape a piece of mirror to the outside of the tank the wrasse may become preoccupied with its own image and leave the others alone

[albano]

IMO/E...6lines do not belong in anyone's tank...they usually become aggressive and kill other fish, even those larger than themselves.
New fish should have gone into QT first for observation, but whenever adding new fish to the tank, it is best to use an 'acclimation box' so that the new and old fish can check each other out for a day or 3 without any actual contact.

[cherubfish pair]

If the newcomer hides in a corner, prop up and small square of egg-crate in the corner for protection. The fish can still see and get food but the aggressor should leave it alone.

I'm doing this now with a sixline and purple dottyback newcomer. The sixline finally left the other alone and the dottyback is venturing out of the corner a little at a time.

[cstonge72]

Thanks for all the tips! Appreciate it.

[snorvich]

Take out the sixline.

[SaltieG]

I hope my sixline never becomes like these others I hear about. Mine doesn't bother a soul. He just zips in and out of the rocks minding it's own business.

[sreefs]

I use an acclimation box for all new additions in my 135. I would also get rid of the sixline in a 30 gallon, nothing but trouble.

[cstonge72]

The gramma died. I'm seriously considering taking out the 6 line now.

[NYCBOB]

I hear stories of aggressive 6-line all the time. I have had 3 so far, and none was ever aggressive.

[ca1ore]

Marine fish can be incredibly territorial and new introductions are always at risk. Having said that, there are a few things you can do to help the odds:

1. QT all fish, for disease yes, but also to heal them up, get them eating well so they can build up reserves for the 'gauntlet' they must run upon introduction to the main display
2. Be aware of incompatibilities; some fish just don't tolerate other fish no matter what you do; six-line, some tangs and some dottybacks I'd put in this category.
3. Consider using a socialization box; it's not foolproof but can alert you of potential problems before they become problems
4. There are an array of tools to try to reduce aggression (mirror, rearrange rockwork, small signs) that can work

[Nace]

You say you lost a couple fish, and now the Gramma died.

Did the six-line kill the other two fish as well?

Keep in mind it is not just the size of the fish that matters in regards to tank, but temperament,swimming patterns, etc..

I also would QT any new additions. A QT tank does not have to be expensive.

[cstonge72]

One fish mysteriously disappeared (purple firefish) & a blenny jumped the tank.

I've removed the 6-line.

[Nolanryan]

6 lines are the devil! How much fun was it removing him from the tank?

[cstonge72]

Lol. Took 45 mins. and had to take out almost every rock! My anemone cut loose and got sucked against and then blown around by an air pump. Freakin ridiculous!!!!

[Brikki]

Have a six line that keeps my royal gamma to one side of the tank. He doesn't mess with the yellow tang, big percula or my firefish. It's a shame they can be punks because they are beautiful.

[snorvich]

You say you lost a couple fish, and now the Gramma died.

Did the six-line kill the other two fish as well?

Keep in mind it is not just the size of the fish that matters in regards to tank, but temperament,swimming patterns, etc..

I also would QT any new additions. A QT tank does not have to be expensive.

Exactly.

[myram]

I always add new fish after the lights go out for the night. About 1 hour after the lights go out, I get the new fish from the QT tank and bring it to the display and put him in. That way most of the other fish are sleeping and won't even notice it until the next day.

[coralsnaked]

I put agressive fish in time out. I have clear plastic wide mouth (quart sized for small fish and gallon sized for large fish) screw top drink containers that I have drilled holes in a lattice fashoin around the entire container. I simply catch the fish and place in container and in the tank where he resides. A couple of days usually does the trick. When they come out they are all reabilitated and feel like the new kid on the block. Repeat offenders are then sent to the penitentiary LFS as I do not beleive in the death penalty.

[druckle]

This a little long but maybe it will help you.

How I "Cured" my super aggressive Purple Tang.

I added a 3-4 inch purple tang with the first 5 fish that went through quarantine and into a new 225 display tank.

Recently I attempted to add some new fish. What a disaster. The purple tang was OK with the fish that went in the tank at the same time as him but would not tolerate ANY new fish added after him. After he murdered the next three fish that went in the tank I decided I would never have more than 5 fish if he didn't come out of there. A fish trap baited with Nori and about an hour of my hand on the trigger caught his nasty butt and he went back into a quarantine tank for several weeks.

At this point I was about ready to see if I could find a good home for him with another aquarist but a friend suggested that I build a "isolation chamber" in the 225 and try putting him in there for quite a while to see if all the fish could become accustomed to each other and allow a relatively peaceful coexistence.

I built a 18X10x10 rectangle from small diameter PVC pipe and covered all sides except the top with the type of plastic netting normally used to keep fish from jumping out of a tank. The isolation chamber floated nicely within the 225 providing great vision in and out but safety for all if war was threatened again.

The purple tang went in there and immediately a harmless war erupted between an infuriated purple tang and the other tangs (I had successfully added a powder brown, a hippo and a naso while the criminal purple tang was in quarantine/isolation). (Yes...I love Tangs).

The war lasted a couple of weeks with a lot of posturing and mutual attempted attacks but it faded away and everyone seemed to ignore each other. I thought that it might be well to move the floating isolation chamber from one location to another now and then just in case the purple beast marked out one location as his territory.

After several more weeks I decided "now or never" and release the purple guy into the main tank. Wonder of wonders ....it seems to have worked. All fish busily search for food and ignore each other. The only aggression is between the powder brown tang and a rabbit fish which for some reason the powder brown doesn't like. Nothing ever comes of that because the Rabbit Fish just raises his poison spines and the Powder Brown seems to understand that there's not much he can do to rid the tank of his enemy.

With the success of that, I decided that any new fish in the future were going to go through the in-tank isolation cell before they got their freedom. I've successfully added a medium sized yellow banded maroon clown and she totally ignores two Ocellaris clowns. I'm not sure that situation will hold as the maroon matures but for now I count it as a success.

My experience with this "isolation in plain view" scheme has been so positive I thought it might be worth sharing in case other folks might want to address their own issues with fish aggression to see if it works for them.

[postshawn]

The six lined wrasse needs more room if it's going to share space with other inhabitants. That load was too many for a 30 gallon. If you had 3 fish I would think that would be a good amount to stay with. Maybe a small non aggressive addition but be careful. Royal Gramma's can be aggressive and territorial too. I'd look on somewhere like www.liveaquaria.com for the basics of aggressive and community fish info. Along with a Clown, Cardinal and Pygmy Angel if you wanted to add more fish might I suggest one more of the same type of cardinal as they do well in group. Or maybe a Firefish of which there are many varieties and all are community safe. Chromis are basic but actually pretty cool fish to watch. Or if you wanted a wrasse maybe a Fairy Wrasse. But as with all wrasses be sure to have a tight lid.

Also when adding fish if you re-arrange your rock work in the tank and then add the new fish right after that helps with aggression too. Doing that means the fish have to establish all new territories and the new fish will be there for the establishing so they should get a fair chance. Otherwise in a 30g all the territories are already established and added fish will have no where to go for safety.

Good luck.

[snorvich]

I always add new fish after the lights go out for the night. About 1 hour after the lights go out, I get the new fish from the QT tank and bring it to the display and put him in. That way most of the other fish are sleeping and won't even notice it until the next day.

Good practice. I do the same.

[Kaman8]

This a little long but maybe it will help you.

How I "Cured" my super aggressive Purple Tang.

I added a 3-4 inch purple tang with the first 5 fish that went through quarantine and into a new 225 display tank.

Recently I attempted to add some new fish. What a disaster. The purple tang was OK with the fish that went in the tank at the same time as him but would not tolerate ANY new fish added after him. After he murdered the next three fish that went in the tank I decided I would never have more than 5 fish if he didn't come out of there. A fish trap baited with Nori and about an hour of my hand on the trigger caught his nasty butt and he went back into a quarantine tank for several weeks.

At this point I was about ready to see if I could find a good home for him with another aquarist but a friend suggested that I build a "isolation chamber" in the 225 and try putting him in there for quite a while to see if all the fish could become accustomed to each other and allow a relatively peaceful coexistence.

I built a 18X10x10 rectangle from small diameter PVC pipe and covered all sides except the top with the type of plastic netting normally used to keep fish from jumping out of a tank. The isolation chamber floated nicely within the 225 providing great vision in and out but safety for all if war was threatened again.

The purple tang went in there and immediately a harmless war erupted between an infuriated purple tang and the other tangs (I had successfully added a powder brown, a hippo and a naso while the criminal purple tang was in quarantine/isolation). (Yes...I love Tangs).

The war lasted a couple of weeks with a lot of posturing and mutual attempted attacks but it faded away and everyone seemed to ignore each other. I thought that it might be well to move the floating isolation chamber from one location to another now and then just in case the purple beast marked out one location as his territory.

After several more weeks I decided "now or never" and release the purple guy into the main tank. Wonder of wonders ....it seems to have worked. All fish busily search for food and ignore each other. The only aggression is between the powder brown tang and a rabbit fish which for some reason the powder brown doesn't like. Nothing ever comes of that because the Rabbit Fish just raises his poison spines and the Powder Brown seems to understand that there's not much he can do to rid the tank of his enemy.

With the success of that, I decided that any new fish in the future were going to go through the in-tank isolation cell before they got their freedom. I've successfully added a medium sized yellow banded maroon clown and she totally ignores two Ocellaris clowns. I'm not sure that situation will hold as the maroon matures but for now I count it as a success.

My experience with this "isolation in plain view" scheme has been so positive I thought it might be worth sharing in case other folks might want to address their own issues with fish aggression to see if it works for them.

Can you make a pic of your isolation cell? My flameback angel has killed my multicolor angel