White spots... Definitely not Ich.

Question
QUESTION: I have a 5 year old iridescent shark named Whiskers. We've been through many tanks and many fish together and he's been getting sick. First he had Ich and no medicine worked on him because he's scaleless so we had to go herbal. I raised the water temp, changed some water, added some nice salts and stresscoat, lit some candles, etc. he's much better now. However, that was months ago and now it seems he's got something wrong again. His lips appear to be swollen with what I can only describe as "acne" spots. It almost looks like he burned himself or had an allergic reaction (probably not though). I've seen a lot of fish diseases but this one is stumping me.  
Please help!
Madde

ANSWER: The best way for me to help is to have you upload a picture. If it looks like burns, then I would say ammonia and/or nitrite poisoning. What are your readings on both? How often do you test the water and do water changes? have you added any new fish recently? Is the heater and filter working properly?

---------- FOLLOW-UP ----------

QUESTION: Nitrite is fine, ammonia is a little high. I haven't added fish and the heater and filter are both working fine. I'll put a dose of ammo-lock in and see if it helps.
Thank you,
Madde

Answer
You can add the ammo-lock, but those types of "medications" rarely work. If the ammonia is higher than zero, then there is too much in the water. The fastest and safest way to get the ammonia back to zero is by doing daily water testing and water changes until the ammonia is gone. Weekly testing and water changes helps ensure that the ammonia and nitrite levels do not rise.