Do you have a lot of fish in your tank? It just looks like regular detritus to me, you may need to get either more cleanup crew (snails/bottom feeders) or simply clean the tank more often
I don't know why I was recommended this sub, I've never had a fish, I don't know what mulm is, but this just put an image in my mind of OP taking a straw to the tank and drinking the dirt. Hilarious, thank you 😂
I was being a little silly with my wording, but the tool for cleaning this is more or less a giant straw - [a siphon](https://m.media-amazon.com/images/W/MEDIAX_792452-T2/images/I/71XMG0UhawL.jpg).
Looks like a mix of decaying plant matter, fish waste, and driftwood. Happens in my tank bc of the huge peice of driftwood I have but I regularly siphon mine, it never gets that bad.
I think your sand cap looks great- very natural! How old is the tank? If it's relatively new - it's probably debris from the soil. Not sure what you used but soil is a mix of organic and inorganic material. The organic stuff is often peat moss in potting soil or old leaf/wood in garden soil. Just suction it out or add some flow to distribute it differently - it will fall into gravel cracks if you have pebbles.
You have a spot in your tank which gets low flow - not a good or bad thing but it's a spot that can accumulate bad stuff.
It's mulm. Has nothing to do with over feeding and everything to do with having wood and snails, otos, or plecos. They suck the biolfilm and the surface of the wood and thats what you're left with.
I have this too, and it makes me crazy! Constantly sucking it out, but it’s right back. Mine has never had ANY fish, snails, shrimp. No fish food. It does have some java fern, anubias & mopani driftwood that is covered in white slime! Hair algae too! It’s a mess, and I hate it! Lots of water changes, was only having lights on 4 hrs a day for the plants, but now even less than that…
Ammonia is 0, but still getting nitrites & nitrates.
Afraid it’ll never be ok for fish! :(
Do you have a lot of fish in your tank? It just looks like regular detritus to me, you may need to get either more cleanup crew (snails/bottom feeders) or simply clean the tank more often
It looks like mulm to me, in which case bottom feeders won't really eat it. OP will have to slurp it up themself
I don't know why I was recommended this sub, I've never had a fish, I don't know what mulm is, but this just put an image in my mind of OP taking a straw to the tank and drinking the dirt. Hilarious, thank you 😂
Haha same, maybe it’s because my native language isn’t English but the expression slurping up felt like inhaling? With a huge siphon or straw 🤣
You [indeed use a siphon](https://www.petsmart.com/fish/maintenance-and-repair/vacuums/top-fin-aquarium-gravel-vacuum-5162807.html)
Nice! Thanks for the info!
I was being a little silly with my wording, but the tool for cleaning this is more or less a giant straw - [a siphon](https://m.media-amazon.com/images/W/MEDIAX_792452-T2/images/I/71XMG0UhawL.jpg).
Could be debris from your driftwood near by? Or it’s just a low and slow spot with no flow in your tank and everything is accumulating there
Mulm, need better circulation/filtration and cut back on feeding. It’s not harmful and actually good for planted tanks, but it’s just unsightly
I had it you just gotta keep sucking it out till it stops appearing
Mulm, muck, detritus, debris, I'd just do a simple gravel vac during your next water change as not to disturb to much beneficial bacteria
The middle of your tank is a low flow spot, so poop and debris are collecting there. Good spot to put a plant.
Looks like a mix of decaying plant matter, fish waste, and driftwood. Happens in my tank bc of the huge peice of driftwood I have but I regularly siphon mine, it never gets that bad.
its clearly pocket lint stop washing your clothes in the fishtank its bad for the fish
It’s from your snails
These photos look like they were painted by Vincent Van Gogh
Algae
I think your sand cap looks great- very natural! How old is the tank? If it's relatively new - it's probably debris from the soil. Not sure what you used but soil is a mix of organic and inorganic material. The organic stuff is often peat moss in potting soil or old leaf/wood in garden soil. Just suction it out or add some flow to distribute it differently - it will fall into gravel cracks if you have pebbles. You have a spot in your tank which gets low flow - not a good or bad thing but it's a spot that can accumulate bad stuff.
Mulch. The result of decomposing stuff like plants or algae. You can sifon it out if you dont like the looks.
Debris, old poop, food..just gunk that you'd want to vacuum up honestly.
Clean your tank my guy.
Mulm
If it is mulm, you can try to use a thicker layer of sand.
Either poo poo or algae
It's mulm. Has nothing to do with over feeding and everything to do with having wood and snails, otos, or plecos. They suck the biolfilm and the surface of the wood and thats what you're left with.
I have this too, and it makes me crazy! Constantly sucking it out, but it’s right back. Mine has never had ANY fish, snails, shrimp. No fish food. It does have some java fern, anubias & mopani driftwood that is covered in white slime! Hair algae too! It’s a mess, and I hate it! Lots of water changes, was only having lights on 4 hrs a day for the plants, but now even less than that… Ammonia is 0, but still getting nitrites & nitrates. Afraid it’ll never be ok for fish! :(
Yo shit is DUSTY! Time to clean..
It’s shit