my royal blues are sick

[bobcanales]

Guys I need your help, I have a total of 6 discus in a 125 gallon tank, I have 2 reds 2 yellow melons and 2 royal blues, I started a new job so it had been about a week and a half since my last water change I was able to do a water swap 2 days ago and my 2 royals got really dark and look really sick. What could it be any help would be really appreciated. A little about my tank, Temp is between 85 to 87 degrees, I run a fluvial 405 and an custom wet dry sump with bio media, sponges and about 60 bamboo sticks to absorb the nitrates. tank mates are angels a few tetras some loaches, my discus are between 5 to 6 inches, also I was getting that stinky water smell last month so I put some carbon in the over flow but its out now

[pcsb23]

First thing to do is a largish water change with clean water. Next drop the temps a tad, 82 - 83 is fine after that fill this out http://forum.simplydiscus.com/showth...lease-complete

[bobcanales]

Ill do it when I get home today, Ive had them for about 5 months, I got all 6 around the same time and the other guys are doing ok, I use municipal water treated with prime, someone told me that they don't like carbon could that have done it?

[pcsb23]

Carbon? Simple answer is no.