Dark discus

[AllThingsPets]

Hi all!
About 1 1/2 months ago, I got 11 Discus for my 150 gallon tank. Within the last few weeks, one of the discus has darkened significantly and is almost black. All the other discus are fine, and there are no apparent problems with the water quality. Ammonia is 0, nitrite is 0, nitrate is 5, pH is around 7, and there is plenty of surface agitation so it is well oxygenated. Temp is 84 F. The darkened discus doesn’t appear to have any other problems, and is behaving normally, if a little shy. Eats ok during feedings. I don’t know what could be causing this change in the fish. I’ve read that it could be the discus showing stress, but I really can’t tell what could be stressing this little guy out. If anyone has any ideas on what the problem is or suggestions to fix it that would be great!

Discus as of May 6



Discus as of May 17

 

[nikm128]

How long has it been dark like that? Some of mine will also occasionally get a bit darker than usual for what seems like no reason and then be fine in a few days

 

[AllThingsPets]

How long has it been dark like that? Some of mine will also occasionally get a bit darker than usual for what seems like no reason and then be fine in a few days

About a week

 

[nikm128]

Well, obviously you change water pretty often to have only 5 nitrate so I don’t think it would be something else in the water bothering them. Based on the pictures I’m assuming it also doesn’t try to hide by itself either?

 

[AllThingsPets]

Well, obviously you change water pretty often to have only 5 nitrate so I don’t think it would be something else in the water bothering them. Based on the pictures I’m assuming it also doesn’t try to hide by itself either?

Not really. Occasionally it will go hang out in the plants by itself but I’ve noticed all of them doing that from time to time. They tend to like to stay together though, or in groups of 3-5

 

[nikm128]

Well this is a puzzle, is there anything that could’ve gotten into the tank by accident? Say perfumes or fumes of cleaning products?
86 ssinit RollaPear

 

[AllThingsPets]

Well this is a puzzle, is there anything that could’ve gotten into the tank by accident? Say perfumes or fumes of cleaning products?
86 ssinit RollaPear

It certainly is . I’ve always found the hardest part of fish keeping is just trying to figure out what the problem you’re having is. I doubt anything could have gotten into the tank, as there are glass lids that cover most of the surface. Do you think it could be some sort of parasite or other internal infestation?

 

[nikm128]

I suppose it’s possible for one to be in an early stage, but I didn’t mention it because that usually involves very little or no appetite at all. Weird to be effecting only one discus though

 

[86 ssinit]

Well welcome to discus keeping . I’ve got lots of questions. How old is the tank and what else is in it? How often and how much water do you change weekly? Where did you get your discus? What are you feeding? What type of filtration? Was the tank a planted tank before discus?

To the fish. There is something off and it’s hard to say. In the first pic he’s got a crescent shaped cut on him. He not that dark and looks new to the tank. In the second pic he looks bad. That’s a stressed or sick fish. But back to the third and it’s not as bad. Yeah it’s stressed but it could just be low fish on the pecking order. Need that info above.

Next your plants may be struggling. Just from the pics it look like the lace plant is dying off. I haven’t had much luck with lace plants. They just can’t handle the heat. Was this an established planted tank that you raised the temp on for discus? Being it’s got substrate and planted this tank is going to need to be cleaned a lot and vacuumed at every water change. I also do planted. It is frowned upon by discus keepers. Are you using co2?

 

[A201]

Cichlids, especially Discus darken when stressed or bullied. Considering 10 out of the 11 Discus are apparently thriving, its likely the dark Discus is number 11 on the strength chart.
Another possibility is early stages of Hexamita. Look for inflamed sensory pores w/ white oozy discharge & diminishing appetite.
As long as the Discus continues to eat, the chances for recovery are great.

 

[RollaPear]

It looks like a parameter/bac issue so you're going to have to approach this from the ground up.

Everything 86 ssinit and everyone else has asked is right on the money. Additionally I would take the following steps

1. Clean the filter

2. Purchase an "Ehiem guick vac pro" and go over every cm of your gravel substrate. Discus are more prone to bacteria issue than any species I've kept before. It's a situation that can be aggravated if you're feeding beefheart while having gravel. The vac will turn the water cloudy, regardless, so water change right after the vac.

3. Purchase a PH pen and test your water before doing WCs. I find that small PH swings can cause stress. I went through this a few weeks ago where one discus was showing signs of stress, clamped fins and darkened coloration. I ran through the usual tests first and found that the culprit was a small 1.0 PH swing.

I personally find it really difficult to criticise other hobbyists. Especially since I'm nowhere near an expert on the species. But being a planted guy I notice from your pics that there is a lot of debris on your Madagascar, cyrpts, Lotus (I think it's a lotus?) and wood which suggests insufficient filtration and/or flow. Also it's imperative to get a fine sponge pre filter to add to your intake if you're keeping discus.

If you can, please gives details of the tank size and filter model(s).

 

[H Farnsworth]

is it a young female?

 

[86 ssinit]

H Farnsworth how are your discus doing? Do you have a thread running?

 

[H Farnsworth]

I don’t but I really should. Still got em all and they seem happy and healthy.
Oddly enough I have one just like the dark fish in this thread and it too will get extremely dark. Same color and everything.