Swollen Gills

[Demosthenes]

Sorry kesley, I must have missed that fact you don't age your water. This is probably controversial but I'd guess that daily 90% WC's with water that has ammonia and nitrite is worse than doing weekly 30% WC's. If the filter can eliminate the NH3 in 12h from a 90% WC then ~50% of their lives are spent irritated by ammonia and nitrite compared to 4h a week with 30% weekly WC's. Your discus probably won't grow to the same extreme size and beauty that we see on this forum but at least they won't die.

Yeah, this is basically where I have arrived - trying to minimize harm. For what it's worth, I've been keeping other fish in the same water with less frequent water changes and have had no issues.

[White Worm]

That's my point, sometimes 90% isn't always the fix or best when you are changing water straight from tap (many times it is worse). Its not that obvious to the eye but I just killed about 100 angels by doing a water change from tap at 80%. I think I forgot the conditioner but it was quick and they were all either dead or gasping at the surface within minutes. There were no micro bubbles and I let the water splash in like I always do but........That tells me that my water sucks straight from tap. I keep my changes at a safe 50% with proper dose of water conditioner and everyone is happy. For me, API water conditioner is sufficient. I may look into safe though because it does a better job. Prime is just so expensive.

[White Worm]

Yeah, this is basically where I have arrived - trying to minimize harm. For what it's worth, I've been keeping other fish in the same water with less frequent water changes and have had no issues.

Discus just seem to be the most sensitive when it comes to their environment. That's kinda why they have the stigma of being hard to keep. If you can't figure out their source water, they can be. Age your water 24 hours and only use that to do your changes and see if anything improves.

[Demosthenes]

And now I have one fish who's taking a turn for the worse. It's not even one of the fish who had the worst gills. He just stopped eating the last few days and suddenly he's very dark and tail standing. No other symptoms. I have no idea what to do with this.