Dark male discus

[Tefloncat]

100 gallon planted DT (at least my original intention), 6 discus, 4 cacatoides, 2 rams, 2 agassizi, 13 dwarf Cory's, 4 Peruvian (?) otocinclus, 4 "regular" otocinclus, 25 cardinal tetra, 2 stardust sometimes referred to as spotted queen arabesque pleco (l262), 30 gallon sump (including 3 gallon moving bed filter with k1 micro media, matala mat filters, 1 anoxic filter, plenum using black matala to create anoxic zone, 2 sponge filters), aqua ultraviolet 25 watt, AutoAqua AWC touch (100% water change/day, using ro/di with 1 tablespoon of Rift Lake salt/55 gallon drum. Ammonia 0, nitrite 0, nitrate 10, tds 75-80. This all included in my question so you have information. I have 2 breeding pair out of 6 purchased (I'm lucky I guess). NOW my question after 3 months I have a blue male discus (leopard I think) who constantly dark almost black, is mating, great appetite (he's king of the tank), fins are flaired, pretty territorial and the largest. What gives? I use to have discus back in the 80's and had always had good healthy egg laying discus, NEVER this dark. Is it the background, stress fighting for territory. This dark usually means a problem....what gives?
Thanks in Advance
Eric

[BrendanJ23]

Hi Eric,

Can you upload some photos at all? It will give the more experienced keepers a better idea of what's going on, including the tank.

[jeep]

As long as it's acting healthy and normal i'm not sure there's much to worry about. I have some Turks and SS's in a darker background tank an they're always dark. Territorial stress or camouflage is most likely the answer...

[danotaylor]

Both pics show the fish under heavy cover. Could just be environmental since all else seems well. Does he come out from the cover into the light, and if so does he lighten up then at all?

[Mando]

On top of what Dan and Brian said, you said he is mating. That could also be part of the darkening. I notice my wilds sometimes get really dark but never had a problem with them.

[danotaylor]

Do you have a dark background? It's difficult to see from the pictures

[Tefloncat]

Thanks everyone, your answers are confirming my suspicions. I knew background color can effect discus coloration, but it’s just this one male and never thought the color change would be this great. Here’s a few more pics for an idea of how dark the background appears (it’s a universal rock sheet that I cut and the the stump is too -to cover the unsightly overflow). As a side note, my goal was to buy or trade as much of the aquarium from Craigslist, OfferUp, etc. I managed about 90% used and kept it under $1500 including fish! (I’m a bike racer and traded a trainer for the fish and parts for the 6 stage ro/di)

[Tefloncat]

Dark background was my suspicion, but did the other blue variations not go dark and dangerous? Problem child back left corner. As a side note my goal was to build and stock a 100 gallon DT, obtaining everything by trade or purchase from sites like Craigslist, NextDoor, etc. I race bikes and have acquired LOTS of equipment over the years and a trade for a trainer got me all the fish and I manage to keep everything else under $1,500 (~90% purchased as previously owned). It took me about 6 months was a fun challenge. Oh, the round “badge” on the cover is actually a fossil of a fish.

[BrendanJ23]

Just on a side note, how long have you had the discus? The deep substrate looks like an accident waiting to happen, even with 100% daily WCs.

[Tefloncat]

There is a 1.5” plenum below the stratum, which gives an illusion of 4” stratum. The discus have been with me almost 5 months and the male has been that dark since. I’m hoping that isn’t the issue...that would require complete tear down. If it was the issue wouldn’t the water parameters be a problem? Picking your brain, why would the depth lead you to think it might be a problem down the road? The plenum is a 1.5” matala mat with landscape clothe on top then a 1/2” layer of clay (the kind they use for a baseball field) a thin layer of laterite powder, another 1/2” of clay, landscape clothe, then ~2” ADA Amazonia II (back) and pool filter (front). All- in-all about 3-4” of actual substrate. The pH has been a consistent 6.5 so all that crap isn’t really playing havoc with pH or the tds.

[BrendanJ23]

Thanks for clarifying Eric. Well with everything I have learnt from here and experienced first person, it is possible to have substrate of course but not without lots of work. I can't get over how dirty my BB tank gets and thats with daily siphoning and/or WCs, in an under stocked over filtered tank. Additionally , we have no way of measuring bacteria levels in your water. So all the ammonia, nitirite, TDS etc can be measured and be fine, but there may be other elements in the water that we can't test for that could be causing problems. By no means am I saying this is your problem with your fish, I just wanted to bring it to your attention in case it has been overlooked.

[Tefloncat]

I appreciate your insight, I don’t want to have blinders on. I really have never thought of the stratum as a potential problem, and yet it very well could be. I’ve created an anoxic zone in my tank (purposely), and with this zone I could potentially have a lethal or problematic anaerobic bacterial growth and not know it, bringing my attention to it will make me ponder about the substrate. In addition, in the last several hours the darkened male fought with another male and damaged the other discus’s eye, enough to have tissue damage! I’m also thinking really high stress with all the fish in the DT and what with breeding I’m sure it’s not helping. Like you said all the numbers may great but he might be super stressed or possibly running an infection. I’m thinking of moving the darkened male and the female to the hospital tank. If it’s not one thing it’s another.

[BrendanJ23]

Yeah my first thought that was the tank could be over stocked, probably more than I what I would be comfortable with. Combine that with substrate, plus some fighting, it may be a recipe for disaster (sickness or slow recovery, or even a secondary illness). Just food for thought mate.