Hi all,
I'm a newbie, so thanks in advance for any help/advice. I had a small tropical freshwater tank about 10 years ago so know some basics, but have forgotten a lot as well.
Let me set the stage:
About 6 weeks ago I set up a new 20 gal tank with my girlfriend. We let it cycle for a couple of days (heater and filter running) with some flakes added to start the ammonia cycle, then visited the LFS. They recommended starting with a couple of hardy fish, so we got a longfinned zebra danio, glofish danio, and a gourami. They all got along just fine, but after 2 weeks the glofish and gourami had died and the tank was showing elevated nitrite levels, with ammonia and nitrate at acceptable (low) levels. We did weekly 20% water changes and started treating all the water with Prime which we were told would help with the nitrite. After about two weeks the nitrite levels were back down so we bought another two zebrafish to school with the one remaining zebrafish. Both the new fish were slightly smaller than the existing longfinned zebra.
Since the moment the new fish were introduced into the tank, the resident zebra harassed them almost incessantly by chasing them around the tank and in circles. He especially liked chasing the larger of the two fish. He also became more aggressive during the morning feeding period. I know a little chasing behavior is fairly normal, but this seemed excessive and was almost non-stop. After 3 days the larger of the two new zebras was swimming slowly with his mouth open. I put him in a breeder net in the tank just to give him some space from the other fish, but he died later that day. The two fish are now the sole occupants of the tank.
My concern is that the resident zebrafish stressed/harassed him enough to cause his early demise. The existing 2 zebras aren't schooling at all and instead the smaller one tries to stay away from the larger one. I have heard repeatedly that these fish need schools (3-6 fish) to be healthy, but I am worried that any more zebras that I buy will simply be chased to their death. So I have a couple of questions:
1- Is this behavior by the zebrafish normal?
2- I want to establish a healthy fish population/diversity in the tank. How/what type of fish do I add to the tank that won't be harassed by the zebra? Do I add more zebras, or maybe a larger fish species? Ideally I'd like to get fan-tailed guppies.)
Any advice/opinion is REALLY appreciated. Thanks!!!
I'm a newbie, so thanks in advance for any help/advice. I had a small tropical freshwater tank about 10 years ago so know some basics, but have forgotten a lot as well.
Let me set the stage:
About 6 weeks ago I set up a new 20 gal tank with my girlfriend. We let it cycle for a couple of days (heater and filter running) with some flakes added to start the ammonia cycle, then visited the LFS. They recommended starting with a couple of hardy fish, so we got a longfinned zebra danio, glofish danio, and a gourami. They all got along just fine, but after 2 weeks the glofish and gourami had died and the tank was showing elevated nitrite levels, with ammonia and nitrate at acceptable (low) levels. We did weekly 20% water changes and started treating all the water with Prime which we were told would help with the nitrite. After about two weeks the nitrite levels were back down so we bought another two zebrafish to school with the one remaining zebrafish. Both the new fish were slightly smaller than the existing longfinned zebra.
Since the moment the new fish were introduced into the tank, the resident zebra harassed them almost incessantly by chasing them around the tank and in circles. He especially liked chasing the larger of the two fish. He also became more aggressive during the morning feeding period. I know a little chasing behavior is fairly normal, but this seemed excessive and was almost non-stop. After 3 days the larger of the two new zebras was swimming slowly with his mouth open. I put him in a breeder net in the tank just to give him some space from the other fish, but he died later that day. The two fish are now the sole occupants of the tank.
My concern is that the resident zebrafish stressed/harassed him enough to cause his early demise. The existing 2 zebras aren't schooling at all and instead the smaller one tries to stay away from the larger one. I have heard repeatedly that these fish need schools (3-6 fish) to be healthy, but I am worried that any more zebras that I buy will simply be chased to their death. So I have a couple of questions:
1- Is this behavior by the zebrafish normal?
2- I want to establish a healthy fish population/diversity in the tank. How/what type of fish do I add to the tank that won't be harassed by the zebra? Do I add more zebras, or maybe a larger fish species? Ideally I'd like to get fan-tailed guppies.)
Any advice/opinion is REALLY appreciated. Thanks!!!
. Looks like this (|) but nature drew it better. Just net it out and bin in if it begins to overwhelm the top.
