Serious problem with gouramis

[Protein Lee]

Hi, i had 2 opaline gourami in my 10 gallon tank, male and female. Early in this morning at 5am, I witnessed they swim casually. When i looked closely, the female was almost dying and the male swim strangely and kinda inbalance . I also noticed their fins were nipped badly espicially the female one and her long string-like fin attached under her gill were missing somehow like after being cut. Female died sooner but the male stay alive but looked sick. I seperated the male from the main tank after that to look if it get better. As long as I concerned, my gourami always had an issue before. The male like to tease the female (probably cuz of his territorial behavior) but the female never fight back. It's just a week ago the male just stopped doing so and they go along just fine.. But suddenly this happened. Please consider there is also 2 tinfoil barb and 1 rainbow shark.

 

[Delapool]

Hi, welcome to AA

My first suspect would be water chemistry (eg high ammonia or low ph). I've attached some links which may help. Did you get any water test results?

Ammonia-

http://www.aquariumadvice.com/forums/f12/your-guide-to-ammonia-toxicity-159994.html

Test kit-

http://www.amazon.com/API-Freshwater-Master-Test-Kit/dp/B000255NCI


General-

http://www.aquariumadvice.com/forum...ou-get-started-with-your-aquarium-154837.html

Stocking-

http://www.aqadvisor.com