10 Gallon Tank Black, slimey, plastic algae???

I wish I had a photo of it but I had just cleaned my tank of this weird black slime. Basically, I have a 10 gallon tank for my betta. My sister has recently gotten a 6 gallon for her betta and had not been keeping up with water changes. I noticed a weird, black, almost plastic feeling film lining the walls of the tank at the bottom. She ended up using my magnetic glass cleaner to try to clean it off, but of course, it coated EVERYTHING and it was very hard to get it all out. She then puts the same glass cleaner back in MY 10 gallon (without making sure it was rinsed out properly and cleaned) and basically infested my tank with the same algae. I have been having SUCH a hard time trying to get rid of it. I’ve been using algae control treatments and doing regular water changes, and yet it still seems like this algae is popping up. I have even taken the decor out of my tank and rinsed everything down and even boiled some of the pieces to make sure it was 100% clear of everything. The betta moss balls in my tank have been so unhealthy, they’re covered in algae and my betta now has a white fuzz coming from the top of his fin and his fins are rotting! I really do not want to completely restart my tank. This black algae also covers the leaves and stems of my LIVE PLANTS. I can typically just rub it off with my finger but it is becoming such a hassle. Does anyone have any idea what it might be? Could it be contributing to my tanks sudden infestation of algae and the possible fungal disease my fish just caught? I will insert pictures of the current state of my fish as well as a photo of one of my plants still covered with it. I’ve never had issues like this before.



Also in the back of the photo of the plant— that rock is a lava rock. It is supposed to be a redish/orange color. I dont know if you can tell but it is quite literally turning black and it seems like it is making its ways into the pores of the rock as well.

 

Sounds like the start of black beard algae. The stuff is really hard to get rid of. Surprisingly my nerite snails seem to be eating it in my tank.

 

Sounds like the start of black beard algae. The stuff is really hard to get rid of. Surprisingly my nerite snails seem to be eating it in my tank.

I was thinking blackbeard algae as well but in my sisters tank, it never really grew out to look like black beard algae. It only really coated the walls of her tank and when I had picked up a piece from inside the tank it felt like holding a piece of rubber or plastic.

 

I was thinking blackbeard algae as well but in my sisters tank, it never really grew out to look like black beard algae. It only really coated the walls of her tank and when I had picked up a piece from inside the tank it felt like holding a piece of rubber or plastic.

It doesn't go full beard on everything. It turned my one rock black just like your lava rock. My driftwood is what has the beard look.

 

Wow, I am so sorry to hear that this happened to you! I agree with Ghelfaire, it could be BBA. I'm lucky enough that, over the span of 10 or so years, I've never had to deal with this type of algae or most diseases/parasites. I feel very lucky in that case, but that still doesn't help you with your problem. It kind of looks like BDA (brown diatom algae) in my eyes, but this usually grows on hard, flat surfaces to my understanding.

As for the little fuzzy thing, I have never been able to diagnose this. I actually rescued a boy from an abuse case recently, and he had two small, fuzzy white "balls" attached to the tips of his analfin. It had that same look with the small yellowish dot in the middle. I wasn't able to find out what it was, but way I cured it was easy; Just pluck it right off! Both of them came off very easily, with very little effort. He also has a Fungal infection of the slime coat, that I was able to diagnose. Poor boy lived in such horrid conditions, I hope your little one will be okay!

 

I was thinking blackbeard algae as well but in my sisters tank, it never really grew out to look like black beard algae. It only really coated the walls of her tank and when I had picked up a piece from inside the tank it felt like holding a piece of rubber or plastic.

If the algae forms a slimy coating over everything, then it is not BBA. Black Beard Algae get its name because it looks like a a black (or red or brown) facial stubble. It is not slimy. BBA is a type of red algae.


I think you may have an infection of blue green algae also known as cyanobacteria. It is called a blue green algae because it does contain chlorophyll, but it is really a type of photosynthetic bacteria. Like BBA, it can come in many different colors with dark purple being common.

Cyanobacteria is typically an indication that there are too many nutrients in the tank. You said your sister is doing water changes, but you did not indicate how much or how often. With smaller tanks like 10 gallons, you need to do at least 25% water changes weekly.

You might want to do 25% daily water changes or two 50% water changes a week until the cyano starts to die out. Since it is photosynthetic, turning off the tank lights and blacking out the tank will help.

Also, make sure you and your sister do not overfeed your bettas. Feed once a day what they will consume in a few minutes.

Since cyano are a type of bacteria, they will be killed by some antibiotics. However, using antibiotics can affect the bacteria responsible for the nitrogen cycle in your tank, so that type of treatment should be used only when all other attempts fail.

 

If the algae forms a slimy coating over everything, then it is not BBA. Black Beard Algae get its name because it looks like a a black (or red or brown) facial stubble. It is not slimy. BBA is a type of red algae.


I think you may have an infection of blue green algae also known as cyanobacteria. It is called a blue green algae because it does contain chlorophyll, but it is really a type of photosynthetic bacteria. Like BBA, it can come in many different colors with dark purple being common.

Cyanobacteria is typically an indication that there are too many nutrients in the tank. You said your sister is doing water changes, but you did not indicate how much or how often. With smaller tanks like 10 gallons, you need to do at least 25% water changes weekly.

You might want to do 25% daily water changes or two 50% water changes a week until the cyano starts to die out. Since it is photosynthetic, turning off the tank lights and blacking out the tank will help.

Also, make sure you and your sister do not overfeed your bettas. Feed once a day what they will consume in a few minutes.

Since cyano are a type of bacteria, they will be killed by some antibiotics. However, using antibiotics can affect the bacteria responsible for the nitrogen cycle in your tank, so that type of treatment should be used only when all other attempts fail.

I do regularly test my water and make sure everything is in order in regards to pH, nitrites, nitrates etc and in general, have never really had issues with anything. My sister had used a magnetic glass cleaner I have in my tank to get rid of this same algae I have now, but before putting it back in my tank she didnt make sure it was rinsed or anything. When I was trying to figure out the root of the issue, only reason I know she cross contaminated my tank with the algae in her tank is because the same glass cleaner ended up being covered with the black, slimey algae on the inside when I had unstuck the magnets from each other. I have a 10 gallon and as for right now have been doing about 50% water changes. I gave up on trying to use algae treatments since it doesn’t seem like its doing much to solve the problem. I’m thinking of just moving my betta into a spare tank, fill it up with the water thats already in the 10 gallon and just completely recycle/redo the 10 gallon. I’m all out of luck with trying to get rid of this bacteria.

 

Wow, I am so sorry to hear that this happened to you! I agree with Ghelfaire, it could be BBA. I'm lucky enough that, over the span of 10 or so years, I've never had to deal with this type of algae or most diseases/parasites. I feel very lucky in that case, but that still doesn't help you with your problem. It kind of looks like BDA (brown diatom algae) in my eyes, but this usually grows on hard, flat surfaces to my understanding.

As for the little fuzzy thing, I have never been able to diagnose this. I actually rescued a boy from an abuse case recently, and he had two small, fuzzy white "balls" attached to the tips of his analfin. It had that same look with the small yellowish dot in the middle. I wasn't able to find out what it was, but way I cured it was easy; Just pluck it right off! Both of them came off very easily, with very little effort. He also has a Fungal infection of the slime coat, that I was able to diagnose. Poor boy lived in such horrid conditions, I hope your little one will be okay!

I have thought about just trying to pluck it off since it doesn’t seem to be like an actual fungal infection thats affecting/getting to his entire body. It only really stays at the tip of the fin and makes it look like he has a little pom pom on the top of his body lol. I just wasn’t sure how safe it really is to just pluck it off. This is also my first time dealing with an algae thats this bad. I’ve had the little hair algaes that pop up on some woods but my snails typically would get right to work and just clean it all up. This is actually my first time owning a betta— I’ve only ever really dealt with fancy goldfish and black moor’s and I think we can all agree that goldfish are probably one of the dirtiest to have in tanks. So its surprising I’ve never ran into an issue with my goldfish and yet run into the most puzzling issue with my first betta! Whatever this is, it is extremely stubborn and I am thinking of just completely redoing my tank/re-cycling it and just move my betta into a temporary tank until then.

 

I have thought about just trying to pluck it off since it doesn’t seem to be like an actual fungal infection thats affecting/getting to his entire body. It only really stays at the tip of the fin and makes it look like he has a little pom pom on the top of his body lol. I just wasn’t sure how safe it really is to just pluck it off. This is also my first time dealing with an algae thats this bad. I’ve had the little hair algaes that pop up on some woods but my snails typically would get right to work and just clean it all up. This is actually my first time owning a betta— I’ve only ever really dealt with fancy goldfish and black moor’s and I think we can all agree that goldfish are probably one of the dirtiest to have in tanks. So its surprising I’ve never ran into an issue with my goldfish and yet run into the most puzzling issue with my first betta! Whatever this is, it is extremely stubborn and I am thinking of just completely redoing my tank/re-cycling it and just move my betta into a temporary tank until then.

Haha, I'd have to agree! I used to run a Goldfish rescue/foster and currently run a Betta rescue/foster, and funny enough, all of the problems have come up with Bettas! Sure, I had rescued a giant Comet Goldfish with Dropsy and another with tumors, a Hibuna with ammonia burns, and a few others with issues, but I never had to deal with fungus, pop-eye, HITH disease, or many others until I got into Bettas. I suspect it's because our domesticated splendens friends are much more inbred than Goldies, but that's just my theory

I currently have 12 Bettas (5 of which are "foster fails"). They're all wonderful creatures, but I'm starting to get into carp again. I'm excited!