Brown Algae or Brown Fungus? (with Microscope Images)

[alar01]

Hello all!
Before this post kicks off, I just wanted to say I'm not really concerned about the status of my tank... It should sort itself out eventually. I am more curious about the opinions on what this stuff is!

I set up my first planted tank about 4 weeks ago, and it's having a few issues. Mainly, the wood and plants are covered in this fuzzy brown fluff.
To start this whole mess off, I had planned out and set up hardscape, boiled the spiderwood, and glued rocks to them. My critical mistake was gluing a small (un-boiled) piece to the main pieces to fill out some empty space. Then I put the hardscape in the tank with substrate, filled it with water and let it sit for about 6 days to get rid of some tannins and ammonia spike from the aquasoil capped with flourite. The tank had a cardboard surround to stop stray light from my windows.

After I removed the cardboard (3-ish days in), I noticed a brown fluff covering the little stick that didn't get boiled. Then it started spreading rapidly. At day 6 the rest of the wood had a light coating, and the glass too. Then the plants arrived, I drained the tank thinking it might be normal, scrubbed some of it off, and planted everything. After a week the leaves were covered with brown fluff, but it spread most in the dark areas of the tank; Under the logs, bottoms of leaves, coating the inside of the filter. At week 3 I had enough and bough 3 panda garra (LFS recommended, I know technically fish-in cycle but water parameters are stable with 0 ammonia and 0 nitrite), some amano shrimp, and some ramshorn snails. They've started to pick away at it slowly, and it doesn't seem to be coming back post week 4, but it got me curious. After a lot of searching, I never found anything online about people with similar looking algae. Everyone with brown algae said "diatoms" and that was the end of it. But I'm not sure if that's the case for my tank.

I included some pictures of my tank and the images I took through my microscope. There are no chloroplasts/green in it, which is intriguing, and made me consider a type of fungus. The round picture is from when I noticed it originally (still contains brown color inside the "body tube"), and the other microscope image is from today (looks like an empty hull, with brown particles all around). I know there is the typical algae in the tank; some BGA, diatoms, etc., but this seems different.

Has anyone had any any experience with something like this? I'm very curious to hear some thoughts!
(If people are interested, I also have microscope images of the microfauna I've found in the tank.)

Tank specs.

• UNS 60U
• Chihiros WRGB II 10th edition @ ~30% brightness, 4 light - 3 siesta - 4 light
• Seachem Tidal 35
• Heated to 22C

Thanks!

 

[Simon Cole]

I just wanted to say I'm not really concerned about the status of my tank... It should sort itself out eventually. I am more curious about the opinions on what this stuff is!

Then you certainly belong here. Welcome to UKAPS

Species from the Phaeophyceae class of freshwater brown algae can have fewer chloroplasts and some live in very low light conditions, in addition to forming tufts and filaments depending upon environmental conditions. Did you stain for chloroplasts? I think your first photograph shows diatoms growing epiphytically on filementous algae. Not sure about the second photograph - best to add a scale for size, but it does look more like fungal hyphae so check for sporangia at the tips. Other staining techniques might help disambiguate the sample.

 

[Fishfur]

Wouldn’t it be very unusual for one of the very few freshwater Phaeophyceae to show up? Just curious, I am no sort of biologist or expert where algae are concerned.

A brownish, translucent & rather slimy growth is something I see often on new wood that hasn’t been treated with heat or chemicals like bleach.

I have no idea what it is but it is usually eaten by snails fairly quickly. Snails make a handy clean up solution to this kind of growth.

 

[alar01]

Species from the Phaeophyceae class of freshwater brown algae can have fewer chloroplasts and some live in very low light conditions, in addition to forming tufts and filaments depending upon environmental conditions.

Definitely an interesting idea! I looked into Phaeophyceae and it could fit the bill, but there does not seem to be a lot of widely available information on it (especially in an aquarium). I don't have stains on hand... might need to order some.
Any suggestions for useful stains in this case/to have around? (I'm not a biologist either lol)
Both of those images were about 200x magnification, but I don't have an accurate measurement.

Image 2 on this post is what I'd assume to be septate hyphae. It has a clearly defined septum and possible nucleus, but no visible color under brightfield, darkfield, or DIC. Couldn't find any sporangia.

A brownish, translucent & rather slimy growth is something I see often on new wood that hasn’t been treated with heat or chemicals like bleach.

I am getting my fair share of the white bacterial mold/biofilm on the spiderwood, but this brown stuff seems to be much different.
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I've included a few other pictures. When this started spreading across the tops of the wood, the undersides had already been completely covered (Pic 1, short fluff along entire length of piece). It started as a single point and expanded to a carpet within approx. 2-3 days. A scrub and water change spread it across the entire tank & plants. It's microscopic appearance was that of image 2 (from the message above), but as time has passed, it has grown longer and changed (to the look of image 1 from above).

Not sure what to make of it... just though I'd add a little more info!

 

[Simon Cole]

Have a look <here> and scroll to the appendix. Microscopy-UK is one of a number or <microscopy clubs/socities>; I'm sure it is just a question of asking around. The wood and rocks are very well arranged in your aquarium.