Originally Posted by bigvince
i have no clue would my female jack demp kill them she is bout 4 in i figured she would of ate the gold fish ? i see her mess with the placo some times i had 2 the larger one is 4 in the other was like 2 to 3 ? i have a 55 gal tank divided i have my female and large placo on one side and 7 other fish ( 2 cichlids, 1 jack,2 mollys , a puffer , and a gold fish no problems or issues with them the funny part is the fish get along well alot of hideing places for them all and water test show no problems?
I see you joined us in April, and I don't recall welcoming you yet, so first off, welcome to Tropical Fish Keeping forum.
Now to the bad news. You have a mix of fish that should never be put together in the same tank. The two named cichlids, Jack Dempsey and Convict Cichlid, are not community fish in a tank as small (to the fish) as a 55g. You can read more in the profile, click the shaded names. [Profiles are under the second tab from the left in the blue bar across the top of the page, and the minimum tank size, water parameters, compatibility issues, etc are included for each species.]
There are problems with the other fish too. Goldfish should not be in with tropicals. A puffer depending upon the species may be brackish water, and regardless of that is best on its/their own in a smaller tank. And if the pleco was the common pleco, it attains well over a foot in length and has a significant impact on the tank's biology due to its waste.
I realize you may thing they are getting along now, but they may well not be. Inappropriate spaces [and dividing up the tank is making this even worse] and inappropriate tankmates will stress fish considerably, and this causes health issues and a shorter lifespan. You can read about stress here: http://www.tropicalfishkeeping.com/f...um-fish-98852/
I would strongly suggest re-homing some of the fish before more die. These issues I've mentioned can contribute to "unexplained" deaths.
Hope this is of some help.