sick honey gourami - help
One of 2 honey gouramis in my 25 gal planted sick has fallen ill all of a sudden. He was fine yesterday and this morning I found him lying in the gravel. I immediately out him in a QT. He's swimming OK, but he's 2 whitish spots (pics attached). I have added some salt in the QT. All other fish - other HG, cardinals (10) and harlequin rasboras (7) all seem fine. Water parameters are: ammonia 0, nitrite 0, nitrate 20-40 ppm, pH 6.5. I change 20-25% every week, but last week was out of town and had to skip a week. So changed 30-35% today. I meant to test the water BEFORE the change, but I spaced out. My water has always been good and stable and I can't imagine skipping one week would have had such adverse effect. I mean, even the sensitive cardinals all seem happy. To give some background, this sick HG might have been under some stress as the other HG was the dominant one and does some chasing, but nothing serious (or so it seemed...). Actually, the sick one was the dominant for about a month and lost his power to the other guy. To add some more info, when first bought them I had them in a 5 gal QT. The current sick HG was being harassed by the other one. So I moved this docile one to the main tank first (after about 5 days QT because of the situation..) and then after another 5 days moved the other one. So that time the dominant order had reversed! The docile one in the QT, having been to the main tank earlier, became the aggressor. Again, nothing too serious, just chasing around occasionally. But the old docile guy couldn't hold his dominance too long - after about a month I noticed he went back to being the chasee and now he's sick :( Hope I wasn't too confusing. Both HGs have been in the tank for about 2 months now. I need help in getting this guy alright. Thanks.