Who Gives A Fish Forums

I recently set up a 10-gallon planted tank using leftover cholla wood and substrate from previous builds. Now I've got a couple of pieces with this fuzzy, clear-ish, moldy stuff on them - any idea what it is and how to get rid of it? I'm not super attached to the cholla logs (that baby water fern doesn't seem to be either), so removing them wouldn't be a big deal, but I'd like to keep them if possible.

It's also showing up on the lower part of a leaf stem on another water fern. Could really use some help here. I'm hoping to stock the tank around Christmas time if everything goes smoothly.

I'm pretty sure it's just biofilm, which is completely normal and harmless in a tank. It'll likely clear up on its own over time. If not, it's a great snack for shrimp, snails, or otos if you plan on stocking them. Alternatively, you can just remove the affected area and gently scrub it with a toothbrush to get rid of it.

julia wrote: ↑Thu Jan 09, 2025 8:57 pm I'm pretty sure it's just biofilm, which is completely normal and harmless in a tank. It'll likely clear up on its own over time. If not, it's a great snack for shrimp, snails, or otos if you plan on stocking them. Alternatively, you can just remove the affected area and gently scrub it with a toothbrush to get rid of it.

Thanks for the confirmation, I just wanted to get some extra eyes on it. I'm waiting on my water tests to come back stable, then I'm thinking otos or cherry shrimp, maybe even amano - one of those will make the cut alongside a small cory. Appreciate the input.

There's usually a fungus that shows up on new wood pieces. Rams Horn snails will take care of it pretty quickly. Snails are great for cleaning up and can be a big benefit to a tank, as long as you keep their population under control. If they start multiplying too fast, that's a sign you're overfeeding your fish.

TankWarrior wrote: ↑Thu Jan 09, 2025 11:29 pm There's usually a fungus that shows up on new wood pieces. Rams Horn snails will take care of it pretty quickly. Snails are great for cleaning up and can be a big benefit to a tank, as long as you keep their population under control. If they start multiplying too fast, that's a sign you're overfeeding your fish.

I'm wondering if this stuff also grows on old wood pieces, since these Cholla wood pieces I'm using are from an old tank I broke down due to being too busy. I donated the inhabitants to my trusty LFS and I hadn't noticed this growth on the wood before, but it makes sense that it could've formed or accumulated while it was drying out.

Don't scrub it off, just trim the excess if it gets too thick. It'll keep coming back until the nutrients it feeds on are depleted, then it'll disappear on its own.

I set up a small tank a month ago and reused an old piece of Mopani wood that had been in another tank for years. Had to cut it down to size, and now I've got a small patch growing on the freshly cut area, while the rest of the wood remains unaffected. I'm guessing it's because I exposed new nutrients to the surface by cutting into it.

I've noticed this stuff on pretty much every new or dried piece of wood I've ever used. It's not a fungus, it's actually a type of bacteria that tends to show up for a bit. Some biofilms can get pretty big and stringy, which freaks some people out, but honestly, you just gotta let it run its course. As other bacteria start to establish themselves, they eventually fall back in the competition. It's all part of the cycle, and it's actually pretty cool. I mean, what's not to love about a hobby where you get to watch slime grow on your driftwood?