Gold gourami attacking tiger barbs?

[sdrone]

I inherited a 30 gallon tank from my neighbors. I had to exchange some of the fish. I've been running with a gold/orange gourami (pretty big) from the original tank, 5 tiger barbs and 3 cory catfish for about 2 months. I moved from the old filter to an Aquaclear 30 about a month ago.

Tests are normally pretty good. About 2 weeks or so ago I started getting significant algae. I've cleaned that up and continued the usual water changes.

The only other change lately is a new heater: I got a Stealth Pro heater for Christmas and installed it in the tank, removing the old heater, the afternoon of 12/25.

In less than 24 hours, 4 of the tiger barbs are dead. Only 1 of them looked like he'd been chewed on.

The barbs nipped the gourami a bit in the beginning, but that stopped in a day or 2. About a month ago, I think they were nipping the cories based on how some of the cory fins looked, but that stopped in a few days.

The gourami seems to spend more time in the bottom half of the tank lately and seems to chase a bit, but I've never seen it attack the other fish. The first barb died overnight last nigth, and 3 have died today.

Anyone ever seen a gourami do this?

 

[i3k]

Highly doubt they died because of the Gourami. There is something else going on in the tank.

How often do you do PWC?
When was the last time you checked for ammonia/nitrite/nitrate?
What's the temperature in the tank?
Do all fish have damaged fins? Possible fin rot?
Are all fish eating?

I would start with a 50% water change.

 

[Gail]

What is your heater on, could the tank be too warm?

Tiger barbs are agressive fish.

I have a gold/orange gourami in my tank too, the gourami chases other fish, but never nips, and cories are non-agressive too.

good luck

(GPG!) gail

 

[sdrone]

Oops, sorry, I completely forgot about this question during Christmas vacation.

I do 15% or 20% water change every week.

Tests every week or every other week are very steady at 0.25, 0, and 40; I may have had a spike to 80 at this time, it's sometimes hard to tell color differences. I have never gotten the color on the ammonia chart column to look like it's zero.

The temp in the tank was 78, dropped to 76.7/77 on Christmas Day when I changed to the new heater. The heater is actually set to 80, but it won't get the tank above 77 degrees.

None of the fish have damaged fins (the exception is one of the cories that the barbs chased a lot when I first got them - his fin has grown back fine).

The fish eat great; it was always entertaining to feed teh barbs, as the 5 of them would swarm the top of the tank. The lone remaining barb seems ok, but is shy and doesn't come to the top very much.

I doubt I get tiger barbs again; I'm trying to talk to the kids into some red fin tetras; the girls like them because they look pink.