golden manquanese cichlids

Question
Hey Lynda-I am a science teacher and I have 'sort of' evolved into the fish thing. I have upgraded to a ~130 gal tank and I have a red devil, 2 jacks, 2(amorous)convict chichi, 2 red-hook silver dollars, a scavenger, 2 golden manganese chichi, and 7 barbs who simply school. There are great hiding places and all of them have done well together. At this point the largest is about 4". I have been gone for a week and when I returned the manganese chichi appear to have rubbed skin (?), particularly on their foreheads. Their caudal fins are shabby as well. The pH is down so I'm attempting to slowly bump that up-also the temp to ~80. I've put in the first dose of Melafix (antibacterial) and have also added Stess Coat. I have literally fallen in love with these expressive critters so any advice will be greatly appreciated. I never knew that fish could be so endearing! Even the sassy ones!

Answer
Hi Kathy,
Red Devils, and Jack Dempseys are true to their name, and should never be kept with any fish, except maybe their mate.  The jack will, as he gets older kill any fish in your tank.  The territorial, and bad tempered Red Devil is not much better.  No fish is a match to these fish, and they should be kept alone.  They do not have these names for nothing, they are really bad fish.
The Jaguar ( managuesnse Cichlid) is a predator, and will eat any fish he can get into his mouth.  Keeping two is very dangerous, even if it is a female, the managuesnse can easily kill.  Your barbs will soon become delicious meals for the fish you have in your tank.
They will stress the other fish in your tank, and bring disease.  Stressed fish always get sick.  Watch your fish carefully.  The convict is no match for these fish.  The red hooks are certainly out of place, and should be quickly removed.  I would remove the barbs too, as well as the convicts.
When putting fish in a tank, you must read up on them or ask if they get along.  Not all fish get along, some are really bad.  
Using chemicals to bring the PH up, or PH down can be deadly for fish.   If you want to bring up the PH do this very slowly, and I repeat very very slowly.  Buy a bag of crushed coral, and a pair of white nylon stockings.  Wash the coral well, and pass the nylons under hot water,  Make a bag, and put 3 handfuls of coral in it.  Put the coral into your filter, and let the water pass through it.  The next day, check your PH.  If the PH is still too low, keep adding, and always waiting one day before adding more until you reach the right PH.
Not all fish like high PH, this too, you must be careful.  A Red Hooks live in a much lower PH.  The highest he can go is 7.0.  This must never be overlooked, we will never be able to change this no matter what we do.  Some fish live in Alkaline water, some neutral, and some acidic.

For now, you must decide what to do with the Jacks, Red Devil, and Jaquar, as you are heading for deception.  If you want to keep them, then the other fish must go...and I would think the red devil too, as keeping jacks, is really not recommended unless they are kept alone or with their mate, and when I say mate, I mean that they must be of equal force, the male, and female, or they will kill each other.  They will not hesitate to kill one of their own kind also, if they have found their mate.  Two's company, and three is a crowd, they will kill the third one with no regret.  You may wake up one morning to a bloody bath in your tank.
Never believe that if you buy them small they will all get along once bigger...this never happens!

There are many cichlids with better temperaments, and just as pretty as the ones you have now.  

This is what I know about the fish you are keeping, so it is up to you to make up your mind on what you would like to do.

I'm sorry this letter brings you such bad news, but unfortunately this is the truth on these fish.
Lynda