Black crud on leaves and general plant sadness

[WhistlingBadger]

Hi, all. The swords and java fern in my 150g are getting a LOT of that blackish, crusty algae on them. I've got a big LED light fixture on a 4 on, 1 off, 4 on schedule. Also, for several months I've noticed the swords looking sort of tired, for lack of a better term. Their growth has slowed, and they often have little holes in the leaves. The combination of these two issues is making the tank look rather sad, and I want to get the plants looking vibrant again.

Nitrite and ammonia 0; Nitrate 5-10 ppm, GH c. 13 d, KH c. 4 d. Temp 75F. Filtered with a large Eheim pro canister filter, assisted by a powerhead to avoid dead spots in the hardscape. Dirt under sand substrate.

So...change the lighting? New plants? Do plants get old? These are the original swords I put in August 2017, so they are fairly venerable as aquarium plants go.

 

[FishGuest5123]

I have it only in one goldfish tank on an anubias. I scrub it off sometimes. Hard to do but new leads grow out green. Anybody have a good answer? @WhistlingBadger is yours hairy (black beard algae) or more tarry and covering leaf?

 

[eatyourpeas]

Do you fertilize them? Your dirt under the substrate may be old enough to have run out of nutrients.

 

[Colin_T]

Pictures of the plants and algae?

Are you adding any types of aquarium plant fertiliser or relying on the sand under the gravel?
As mentioned by eatyourpeas, the dirt might not be releasing anything now.

Plants can get old but swordplants can live for years.

 

[Retired Viking]

I have sprayed my anubias which had BBA with hydrogen peroxide let it sit for 5 minutes washed it off and returned to tank. Some plants took 3-4 times before it was gone over a couple of weeks but it did clear up.

 

[StevenF]

Slowed plant growth and increase in algae are consistent with a nutrient deficiency. I agree the soil is probably deplete in nutrients.

 

[FishGuest5123]

Mine are not in soil. They are in gravel. Lots of goldfish poop and Excel keep them going.

 

[WhistlingBadger]

I don't vacuum my substrate (as recommended by Walstad, peace be upon her), so I think the nutrients get replenished. @Retired Viking this isn't BBA; haven't had that for a long time. It's like a blackish crust. I'll try to get a picture next time I'm over there.

Thanks everybody, T

 

[FishGuest5123]

I don’t want to hghjack your pist but this what mine looks like and thought maybe it’s the same thing. You can see where zI have scraped it off but hard to do so without destroying the leaf. Note new leaf is green.

 

[Colin_T]

There's black algae that is hard to scrape off, and blue green algae that is black in colour that is easy to wipe off and lifts off in a film or sheet and smells musty/ mouldy.

 

[WhistlingBadger]

Yep, that's the stuff, @Deanasue . Except it's pretty much everywhere.

 

[FishGuest5123]

There's black algae that is hard to scrape off, and blue green algae that is black in colour that is easy to wipe off and lifts off in a film or sheet and smells musty/ mouldy.

Mine is black algae. When searching Google, it says to dip plants in hydrogen peroxide and boil decor.

 

[WhistlingBadger]

Mine is black algae. When searching Google, it says to dip plants in hydrogen peroxide and boil decor.

Yeah, I've seen that. Never been quite sure how to dip rooted plants or boil decor in an established tank. Silly google advisors.

 

[FishGuest5123]

Yeah, I've seen that. Never been quite sure how to dip rooted plants or boil decor in an established tank. Silly google advisors.

I have spray in hydrogen peroxide. You will have to uproot the plant though. . Mine is attached to a rock so it’ll work. Goldfish wouldn’t leave the plant alone. Lol!

 

[Colin_T]

Just take the plants out and put in straight bleach for a few minutes, then rinse off well.

Boiling plastic can melt it and cause it to release chemicals.

Most plants can tolerate 5 minutes in straight bleach and that will usually kill algae. Cool bleach is less damaging to plants, whereas warm or hot bleach will melt things.