Multiple Species Chasing Eachother (Its A Mad Aquarium)

[hassan69]

hello i have a large community tank with 8 black widows, 3 male guppies, 2 female mollys, 3 algae eaters, 2 silver/bala sharks, 1 red tailed shark, 4 gold fish and 1 giant danio. All the fish swim together in a large school which I believe is because of the goldfish, all was well apart from the mollys, and black widows occasionally chasing other fish until I introduced the single giant danio which I discovered wasn’t a good idea about 1 minute after. Now the giant danio is chasing all the fish (especialy the bala sharks) and has caused some of the other fish to chase each other to. It isn’t constant but when it starts up it goes for a few minutes before it calms down again. To give you all the details to help with an answer the fish chase each other in this fashion, the giant danio will chase everything mainly the silver sharks, about 2 black widows will chase any other black widow that swims near it, the mollys mainly chase each other aswell as any black widow that swims past, the red tailed shark will randomly chase the guppies and the giant danio, and the guppies sometimes chase each other. These fish do not school in the same species but all swim together mainly in the middle of the tank and are trained to all swim to the top of the tank when I walk up to it and wave when its feeding time. It’s a fairly big tank with plenty of swimming space and hiding places. I did some research on the giant danio and a majority of the info states that it will try to be alpha fish by chasing everyone but will not kill any other fish. As I can’t remove any of the fish any advice is most welcome. 

 

[fluttermoth]

Your problem is that danios are shoaling fish that needs company of its own kind. At the moment, the danio is trying to form a shoal with the other fish, but because they're not danios, it's not going to work.
 
How big, exactly, is your tank? You have a lot of fish, many of which aren't compatible with each other;
 
you have some that like soft water and some that like it hard
you have temperate fish in with tropicals
you have fish that should be in groups of at least six
you have fish that might or can grow very large 
 
Do you know what species your 'algae eaters' are? What variety of goldfish (comets, fantails, moors)?

 

[HarpyFishLover]

How long have you had this tank, and is it cycled... also, what are your water parameters?
Also, to the forums! I've found that this place is a lot more helpful than just Googling everything