are not all that active either. Most of their time is spent chilling out in the plants. They do get a little more active in reduced light.
Your maintainance schedule looks good. The pH in my Discus
tanks is 6.8-7.0. My temp is 86 degrees Fahrenheit. you may want to raise your temp a tad. The tank sizes very from a 90g to a 210g. I have my lights on in those tanks 12 hours. The timers allow me to slowly bring down the lighting. The end of the lighting cycle is LED moonlights which stay on all night.
I don't have alot of problems with diseases, ich, fungus, and the like. But, I do think that your fish may be stressing form your lighting. Discus
tend to dwell in heavily planted, overgrown, submerged woody areas. It is kind of hard for alot of light to penetrate the type of biotope.
As for your suspected gill problem, I had afun in with flukes years back. That could cause the clamped fins. I will leave a link formeds at the end of this post. I have also found that Discus
are a bit finicky when it comes to some meds. Just be careful when using them. I have gone to natural medications like PimaFix and MelaFix. These are to great products and are a natural, herbal remedy.
Here is the link: http://www.fishforum.com/viewtopic.php?t=252