dark discus

[pally]

I have 6 discus in a 60 gal tank. I have only had them for 3 weeks. For the last week one of them has turned very dark, almost black. He is not very active but he is still feeding. Yesterday another one started to look the same. I have tested my water for ammonia, nitrite, and nitrate and all seems ok. Does anyone have any ideas?

[Merrilyn]

Hi Pally, and welcome to the forum. Sorry to hear you're having problems. Lets try to help you.

Okay, now we need to know more about your tank

How long has it been set up (before adding the discus) and did you fully cycle the tank first.

What exactly are your water parameters pH, nitrite, nitrate, temp.

Planted or bare bottom tank, and if planted, do you add fertilizer to the water.

How often do you do water changes, and how much do you change.

Do you use RO or cO2

Discus turning dark is a sign they are not happy about something, and we need to track down what it is

[pally]

Thanks for the reply.
The tank was set up for around 3 months before adding the discus.
My ph is 6.8, Nitrite is 0, Nitrate is around 30mg/l and temp is 29.
I have around 12 plants.
I first filled my tank with treated tap water, but the last 4 or 5 water changes I have used RO water and I have used fertilizer. I do a 15% water change every 1-2 weeks.
Hope this is enough info, thanks for the help.

[leanne31]

Im not that experienced myself but I'd say a combination of the nitrates and only a 15% wc every 1 to 2 weeks may be the problem try doing about 25% wc every 2 - 4 days and see how he goes.

Leanne

[Kaza]

Are you using straight RO water?

[Merrilyn]

Your nitrate reading is a bit high. I'd like to see it below 10 for discus. Try more frequent, and larger water changes for a couple of weeks and see if that helps.

Are you using RO because your tap water is too hard or the pH is too high. Please test some of your tap water after it has aged for around 12 hours and tell us the reading.

Leave out the fertilizer for a couple of months, and see if that makes a difference. Once we get things right, you can start using it again.

Are your fish showing any other symptoms, like white jelly-like droppings, or lack of appetite.

[pally]

I have done a cople more water changes and left out the fertilizer. I never knew that could cause problems.
He is not feeding very much now, but he always come to the front of the tank at feed times. He sometimes swims at 45 degree angle and his gills look a bit inflamed.
My tap water is not great, ph 8.2 total hardness 22 dGH.
I am using ro + hardening salts.
I will keep up the more regular water changes and see how it goes.
Thanks for the help.

[goldenpigeon]

u might want to try aging your water first if it is that bad.

[Merrilyn]

Keep us posted on your progress pally. If the water changes aren't helping, we might need to resort to medications.

[pally]

He is still hanging in there, but no better.
I have increased the water changes and nitrate is low.
I have started an anti internal bacteria treatment that was recomended by my local aquarium store. As there were no sure signs of any paticular disease he suggested that this was best.