PNWaquarist
Aquarium Advice Addict
So, I went on vacation for a week and had our babysitter feed our cats and fish. I came home this afternoon to find the substrate and wood of my 20 gallon high covered in this light brown material. See the attached pics. I've never seen anything like this before. It looks like it came from the top of the tank, as it's on the top of the wood, top of the substrate that isn't covered by wood, top of my Java Fern, top of my sponge filter, etc. The only place where it isn't located is in the back underneath my heater and HOB filter. One cory is dead, two are alive, and I'm not sure about the rest. I'm currently at pH 7.0-7.2, my ammonia is currently ~0.25 ppm, nitrite is 0 ppm, and nitrate is very low (maybe 2 ppm). I just did a 30% WC, overdosing with Prime, will do another tonight, and some more throughout the day tomorrow until I get most of this junk cleaned up.
The tank is a little over two months old. It was cycled for five weeks, to the point where it could process 3-4 ppm ammonia in 24 hours. I've had a shoal of six young Three-lined Corys in there since late June. Tank temp is 77 F, weekly 30% WCs, never had any post-cycling ammonia/nitrite, nitrate is always < 5 ppm. Tank has a AquaClear 30 filter and a sponge filter. The substrate is black sand, about 2-3.5" deep. I have two pieces of bogwood and a piece of "Amano wood" (I think that's what it is... it's twisty and has to be weighed down in place by the bogwood). Plants are Java Fern (rhizomes anchored with plant anchors) and some floating Hornwort. I typically feed small pinches of NLS Small Fish Pellets twice a day and, in its place, frozen bloodworms twice a week. Last WC was 7 days ago.
Any ideas what this is? I don't think that my house-sitter way overdosed the NLS pellets, as there's too much left in the container and it would take almost the entire container to do this. My wife called her earlier this evening and she claims to have not noticed anything on her last visit (yesterday). We've known her for a while and she's been very trustworthy.
My only guess is that the growth could've come from the Amano wood, which has had some sort of fungus growing on it for a while. Could anaerobic bacteria from the fine sand have played a role? I realize that this can happen but, as I mentioned earlier, it's less than 4" deep at its deepest. I did have the shade on the window up while we were gone, but the tank is on the south side of the window and I don't believe that it gets any appreciable direct sunlight. As I was siphoning up some of this gunk earlier this evening, I noticed that it was sticking together with some sort of stringy, fungus-like material.
Anyway, I'm totally confused and would really appreciate any help.
The tank is a little over two months old. It was cycled for five weeks, to the point where it could process 3-4 ppm ammonia in 24 hours. I've had a shoal of six young Three-lined Corys in there since late June. Tank temp is 77 F, weekly 30% WCs, never had any post-cycling ammonia/nitrite, nitrate is always < 5 ppm. Tank has a AquaClear 30 filter and a sponge filter. The substrate is black sand, about 2-3.5" deep. I have two pieces of bogwood and a piece of "Amano wood" (I think that's what it is... it's twisty and has to be weighed down in place by the bogwood). Plants are Java Fern (rhizomes anchored with plant anchors) and some floating Hornwort. I typically feed small pinches of NLS Small Fish Pellets twice a day and, in its place, frozen bloodworms twice a week. Last WC was 7 days ago.
Any ideas what this is? I don't think that my house-sitter way overdosed the NLS pellets, as there's too much left in the container and it would take almost the entire container to do this. My wife called her earlier this evening and she claims to have not noticed anything on her last visit (yesterday). We've known her for a while and she's been very trustworthy.
My only guess is that the growth could've come from the Amano wood, which has had some sort of fungus growing on it for a while. Could anaerobic bacteria from the fine sand have played a role? I realize that this can happen but, as I mentioned earlier, it's less than 4" deep at its deepest. I did have the shade on the window up while we were gone, but the tank is on the south side of the window and I don't believe that it gets any appreciable direct sunlight. As I was siphoning up some of this gunk earlier this evening, I noticed that it was sticking together with some sort of stringy, fungus-like material.
Anyway, I'm totally confused and would really appreciate any help.
