What on earth???

[Reygan2]

I added two zebra danios Friday and they are terrorizing my guppies!! I thought they were peaceful! I'm a little worried that I have too much current in my tank. The top/middle of the tank has the most, but there are definately calm places on the middle sides and bottom. I added a 5 inch air stone which created more current. All of my numbers are good when I test, but the fish seem stressed, even frantic since I added the airstone and the danios. I have a 29 gallon with 2 HOB filters. I can adjust the flow of one, but the penguin 150 doesn't have that option that I know of. What could be happening?

 

[Rutrag]

Danios are schooling fish, and my experience has been that when you don't have enough to school, the fish either stress out and hide or they go the other way and pick on similarly sized fish. If you have fancy guppies, I'd remove the danios regardless as I think they'll out compete the guppies. The other thing you can try is adding some more danios to get a school. They may end up leaving everybody else alone, but I make no guarantees.

 

[librarygirl]

If I remember from your other post....is this the tank you are cycling with fish? If so, you probably shouldn't add any new fish until the tank cycles. Cycling tanks are stressful for fish as it is, you 1) don't want to subject any new fish the toxins in your tank such as ammonia, etc and 2) you don't want to create a scenario like the one above, where all your fish are now more stressed. Cycling is really hard on fish and can cause illness, death, even long-term effects. If you can take the danios back until the tank fully cycles and in the meantime research better tankmates for the guppies, that would be the best option. Good luck.