jack dempsey cichlid very sick

Question
please email me. i have a jack dempsey ive raised him since he was a baby he's about 6in he leans to the side then finds a corner hes either upside down or vertical he still eats icant see anything physically but his mothe is always open in the corner of tank he's leaning sideways. he in a 50 gal tank i have a lg bio filter and 2 airfilters going. i fill tank when evap then add nitromax aand complete care my other cics are ok but slowly catch the disease and soon die. i had a nother afri cic and it basically died the same way.  i know my tank is good. ive had him for about 6-8 yrs do they have an age limit is there medication i can give him please answer me soon he's dying and i dont want to loose him thank you

Answer
Hi Dev,
 It could be that he is getting old but it is also possible that your water quality is not what it should be.

 It is important to not just add water to replace evaporated water, but to actively take out water and replace that.   Ideally, you should be replacing 25% of the water in the tank once a week, every week, to keep your fish happy and healthy.  This assumes that you have a good filtration system (if you have poor filtration, you need to do much more).

-- Ron
  rcoleman@cichlidresearch.com
  Cichlid Research Home Page <http://cichlidresearch.com>