Plec Dead! Will The Rest Survive?!

[xostrawberryox]

Tank has been set up since mid July, started it off with 3 mollies and an algae eater (plec). Been doing the nitrite test ever since and got the all clear last week, so on Sunday we added a Siamese fighting fish who has been quite mellow ever since (he was in a glass vase in the shop though so maybe the move to a large tank was overwhelming?) Looked in the tank this afternoon and the algae eater was upside down in the tank and lifeless Could this be the influence of the fighter because previously he has been so actively swimming about (or perhaps searching for the lack of algae in a new tank?)

Will my mollies (who are very actively breeding) and fighter survive? Should i add another algae eater or not?

Any help would be appreciated, Jo

 

[black angel]

How big a tank and have you been testing for ammonia?
How long has the tank been running and what filtration?
How often do you do water changes and how much