African cichlid with hole in the head disease

Question
Hi, I have two African cichlids that are in separate tanks.One is 16 yrs and in a 120 gallon, the other is 8 yrs and in a 60 gallon. The younger one has gone pale and has lesions on his head although he is eating well. The older one is still dark and has a less amount of lesions than the younger one. I don't know what the ph or alcaline in the tank are. My husband has treated both tanks with metronidazole and done partial water changes but we don't know how to tell if they are cured.
Can you tell us what we need to do to be sure the disease is gone. Will the lesions clear up? Should we treat them again? We love these fish, they are so nice and sociable and I hate to stand by and let them die because we don't know what to do. I really appreciate your help!!!

Answer
Hi Laraine,
Water conditions are very important in the cure of this disease.  Make sure your water is free of ammonia, and nitrates, and that the PH is 8.0 - 8.5 as African Cichlids live in alkaline water.  Your water must be kept very clean at all times to avoid this disease.  Seeing as both your fish have this disease, tells me that water changes are needed more often.  You must change 25% of your water every week to make sure your ammonia is down to zero, and your nitrates safe.  Have these checked before treating again.  You can also buy these small test kits at your pet store which are always handy to have.  If your PH is lower than 8.0, but crushed coral, wash it well, and put it in a mesh bag in your filter to bring up the PH.  It is very important that your water chemistry be perfect before treating them again.  The lesions should be less noticeable now, they should be getting better.  I do not see your fish, so I do not know how bad these lesions are.  You could give them another treatment to make sure that this is cured.
A combination of Metronidazoel, and Chloramphenicol usually cure this disease.
I would also like to mention that feeding fish good quality food, and varying their diet also helps in avoiding disease.  Fish need vitamins, and calcium in their diet, and we find this in quality flakes, pellets, and frozen food.
I hope this helps, and that they will get better.
Lynda