Black/purple hornwort

[jordana12903]

Hi,
My hornwort and gravel is turning black/purplish and I don’t know why. I have a 10 gallon tank with 3 serpae tetras and 3 zebra danios that are happy and healthy. No matter how many water changes i do the problem keeps persisting. Does anyone know why this is happening and how i can fix it?

 

[SaraB]

How long do you have your lights on? Is your tank by a window? It might be a type of algae.

 

[jordana12903]

It is by a window but the blind is usually closed. The light is usually on for about 10 hours a day.

 

[SaraB]

Try reducing the lights to 7-8 hours and see if it helps.

 

[jordana12903]

I already tried that and it didn’t help.

 

[SaraB]

For how long? It should be a permanent change because 10hrs is a bit much. Alternatively how much are you feeding your fish? That might be an issue as well.

 

[jordana12903]

I did it for 2 weeks and now I will make it a permanent change. I feed them twice a day.

 

[libertybelle]

Twice a day is likely more than they need.

Is the blackish stuff slimy. Does it look like the plant is rotting or is it something dark growing on the plant.

From the picture it does look like some kind of algae and you probably want to remove those infested sections of hornwort.

Also if blinds “usually closed” means they’re sometimes open, lol, the sunlight is likely part of the culprit. Even with blinds closed it likely gets some indirect light. Tanks by windows are very VERY hard to keep algae under control in.

 

[jordana12903]

it looks like something slimy and web like is growing on it

 

[NicosAquatics]

Unfortunately those will not bounce back. That’s REALLY bad algae growth. Sounds like you don’t think it’s light. Most likely your water has way too much nutrients. Overfeeding, too much (powerful) light. Good luck