OVER STOCKING EFFECT!!!!

[vfc]

I think your missing the point, or I am?

One of the above posts says "buy 1 Oscar or buy 10" and I agree with this.

In my experience two Oscars fight no matter what size tank they are in. But if you have 4, 5, or 6 O's in a tank the fighting continues but it's distributed evenly. In fact I think the fighting decreases? So the question is: "Does aggression decrease in a heavily stocked tank?" I say Yes, aggression decreases for sure.

Other questions may come up like: " Is heavily stocking a tank healthy for the fish?"
Why do the fish seem to loose aggression in a heavily stocked tank? Are they over stressed? Lack of oxygen is slowing them down? Are the fish totally exhausted from trying to defend their turf they just gave up?
What is heavily stocking vs.over stocking?
Is this the same as large fish in a very small tank?

For the OP's question, in my opinion, Yes aggression decreases in a heavily stocked tank. Is it because the fish are exhausted, stressed? I don't think so but I'm not sure, I think this would show in disease and death. If the fish started dying then people would stop heavily stocking.
Interesting topic

I have timely experience for this thread. I stocked my 150G heavily with small African Cichlids to reduce aggression. After a couple years, the fish appeared healthy and were much larger (as expected). I was doing 50% water changes twice a week as a result of the bio-load. Fish aggression was minimal.

I got tired of the water change workload so I started removing some of the fish to reduce the bio-load and get down to a weekly WC schedule. Once I thinned the herd out about 30%, the fish were noticeably more active. However, the aggression started to increase. Yesterday I lost one of my favorites (Aulonocara German Red) to aggression. I also had to rescue one of my Placidochromis phenochilus from the tank. Interesting thing is that for two years these guys were just fine with the other fish. They were not picked on at all.

So I now think that I was only able to "get away with" overstocking because the fish were too stressed out, and sluggish from elevated nitrates, to fight one another.

 

[erk419]

I have timely experience for this thread. I stocked my 150G heavily with small African Cichlids to reduce aggression. After a couple years, the fish appeared healthy and were much larger (as expected). I was doing 50% water changes twice a week as a result of the bio-load. Fish aggression was minimal.

I got tired of the water change workload so I started removing some of the fish to reduce the bio-load and get down to a weekly WC schedule. Once I thinned the herd out about 30%, the fish were noticeably more active. However, the aggression started to increase. Yesterday I lost one of my favorites (Aulonocara German Red) to aggression. I also had to rescue one of my Placidochromis phenochilus from the tank. Interesting thing is that for two years these guys were just fine with the other fish. They were not picked on at all.

So I now think that I was only able to "get away with" overstocking because the fish were too stressed out, and sluggish from elevated nitrates, to fight one another.

How high were your nitrates on a weekly basis. Usually nirates under 100ppm will not have a effect an on fish. What you said could be the case or the case could also be the fact that there terrioral and when it was overstocked no single fish could really lay claim to a territory so there was nothing to protect therefore nothing to fight over. Once you started thinning the herd out territory began to open up and they tried to claim it giving them something to protect therefore giving them a reason to fight.

 

[Blue2Fyre]

I have timely experience for this thread. I stocked my 150G heavily with small African Cichlids to reduce aggression. After a couple years, the fish appeared healthy and were much larger (as expected). I was doing 50% water changes twice a week as a result of the bio-load. Fish aggression was minimal.

I got tired of the water change workload so I started removing some of the fish to reduce the bio-load and get down to a weekly WC schedule. Once I thinned the herd out about 30%, the fish were noticeably more active. However, the aggression started to increase. Yesterday I lost one of my favorites (Aulonocara German Red) to aggression. I also had to rescue one of my Placidochromis phenochilus from the tank. Interesting thing is that for two years these guys were just fine with the other fish. They were not picked on at all.

So I now think that I was only able to "get away with" overstocking because the fish were too stressed out, and sluggish from elevated nitrates, to fight one another.

I really have to disagree. It is known that the best way to control African cichlid aggression is to overstock. It spreads out the aggression so one fish is not getting picked on all the time. They live in high density populations in the wild. When you removed the extra fish suddenly they were no longer overstocked and the fish began to fight. They could single out certain fish easier so you began to see loses. Also by removing fish that have been well established for years, it messes up the hierarchy in the tank. The fish also begin to fight for dominance.
I have an overstocked african cichlid tank with minimal aggression. Because of the water changes and filters I have nitrates RARELY get above 20. The fish are not stressed, they eat well, are colorful and breed often.

 

[cichlid fiend]

Thanks everyone!!

For me this thread was started cause of something I had noticed with my pikes and I wanted to see if this was just a coincidence or a proven fact.

From what im seeing/hearing its definitely a proven fact. Im not saying I want the headache of a over stocked tank but there is fish out there that we would love to have in are show tanks instead of having them in a tank by there selfs. Like FH's and other fish with that same agression level.

Thanks again for the good info!!!!

 

[vfc]

My nitates were around 100PPMs before each bi-weekly water change. I do have 10-20PPMs out of the tap, so it is very hard for me to keep nitrates low.

The fish were breeding (at least the Yellow Labs whose population grew from 3 to 12 over the 2+ year period). However, the activity level was definitely lower when I had the full stock.

I will be watching my remaining stock closely. So far they are swimming around much faster and only occasionally chasing each other.

 

[TheCanuck]

i agree with stocking africans , but stocking FH's and jaguars and oscars i just dont think they would enjoy the tank as much if they where alone or just had 1 buddy. My one oscar wouldnt except anyone. Then one day i found an oscar that was his best friend. He shoved him a bit but they where friends. It only took 20-30 fish before he accepted one.

 

[SteveR]

How high were your nitrates on a weekly basis. Usually nirates under 100ppm will not have a effect an on fish. What you said could be the case or the case could also be the fact that there terrioral and when it was overstocked no single fish could really lay claim to a territory so there was nothing to protect therefore nothing to fight over. Once you started thinning the herd out territory began to open up and they tried to claim it giving them something to protect therefore giving them a reason to fight.

I think you made the most sensible arguement here.

 

[SteveR]

Good thread this!

 

[DMD123]

At this point I do not consider my tank "over stocked" but it is comfortable for all its occupants. I have 2 cascade 1500's on this tank and do 2x 30% water changes a week.

In my 120g (60x18x26) I have 1x 5" Midas, 5x 4.5" Red Hooks, 1x 4.5" Sailfin Pleco, 4x 1.5" Buenos Aries Tetras.

When all these fish reach full grown size, it will seem very full since they are all active fish. With the Red Hooks getting up to 8", the Midas up to 13", the Pleco up to 12-18" this will be interesting to see what will happen.

As of now the effect of all these fish has been positive. I have noticed my Midas is not very aggressive. He will barely ever react to the Red Hooks even when they steal an earthworm out of his mouth. This has proved to be nice for me because I wanted a community tank with large fish but not an aggressive tank. Time will tell if the Midas when reaching sexual maturity makes a change or continues to be the puppy dog that he is. But so far a "well stocked" tank has had positive results in what is supposed to be a very aggressive fish.

 

[cichlid fiend]

Well put DMD123!!!