Sorry about the lack of info. I realized I posted that with no information to go by it's been a tough day. OK, this tank is 90 gal. planted with java fern, various sword plants currently there are about 18 plants. I run CO2 @ 2 bubbles per second. The substrate is a fine sand this tank has been up and running for a year now and I have only raised Discus over the many years in a 150 gal. tank this one is the 90 gal. with just a few others such as Corry Cat Fish and one 8 inch Black Ghost Knife. These fish have been in this tank for about 7 months I bought these 6 Discus at 2 1/2 inches they grew fast and well except for the one I posted about. I purchased them by mail from a trusted breeder I have heavy filtration with plenty of mechanical, Biological ( Ceramic Rings and Plastic Balls ) and some chemical 1 canister 4 chamber filter with UV light for up to 150 gal. and 1 canister 4 chamber filter for up to 75 gal. 1 hang on filter for up to 100 gal. and 1 hang on filter for up to 60 gal. and a surface skimmer. The water is set at 84 deg. F, Ph is stable at 6.8 using drift wood to buffer. I feed them 3 times a day with live black worms then frozen blood worms and Bio-Gold sinking pellets. Light sours is a Currant Satellite Plus Pro on a 9 hour schedule. I do a 25-30 % water change 3-4 times a week. I add Seachem Prime, Flourish excel, Flourish Iron, Flourish plant food, Seachem Discus Trace. Ammonia is 0, Nitrites 0, The Nitrates are a little high sometimes but not to bad at worse it is 40 but usually 20 because of the heavy filtration there is plenty of surface movement needed because of the CO2. I clean the tank glass once a week and do a partial substrate vacuuming with every water change. The tap water Ph is a neutral 7 and is free from excess Nitrates but a little high in Chlorine I change the water with a hose attached to the sink so I add Prime about 3 times as it fills back up. That should cover it and again I am sorry for the first post I look at it and feel a little stupid. Thanks for the reply.Sorry, but you will need to give us a lot more information before we are in a position to help you.
Answer these questions to give us some clues as to what the problem may be:
- What size of tank are your 6 discus in ?
- How long has it been set up & how long have you had the discus in it ?
- Did you get the discus all at the same time, from the same source, what was that source, and were they all the same size when you got them ? What size was that ?
- What is your water change routine, how often do you do them, and in what quantity of water volume ?
- Is your tank planted & what substrate do you have in it ? What is your feeding routine & what foods ?
- What is your tank cleansing routine ? Tank temp ? pH in your tank, & out of the tap if you use tap water for WC's.