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Discussion Starter · #1 ·
Some of my plant leaves have this brown/black fuzzy fungus looking growth on them. They are actively growing but I don't know if this will harm them or my tank. I have a T5 and my plants are low light cabombas, ludwigia, rotala, bacopas and crypts. Could this be an illness? Is there treatment to remove this fungus looking growth?
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Could you give a little more description of the "fungus" appearance and the tank conditions? Is it a brown coating on the plants (that you can gently wipes from the leaves), or does it look like small paintbrush bristles? Is it a new tank, what size tank, do you fertilize, light duration/day, have conditions changed recently in the tank?

Also, I have never heard of a "low-light" Cabomba. You may have more light in the tank than you think!
 
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Discussion Starter · #3 ·
I missed a comma there, sorry. It is coating the leaves, like moss on a tree, and on my crypt it sprouted a small growth that looks like round brush bristles. Its not a new tank. I've had it set up for about six months. The plants are fairly new. I fertilize with flourish once a week. Its a 20 gallon that gets about ten hours of light per day. I have taken some fish out of the tank, not diseased related, simply rehomed; but the brown growtnh started before the move.
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it sounds like you have black brush algae, and perhaps diatoms? this is harmless to fish... black outs rarely work on this type of algae :( without killing the plants first anyway.
 

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I've never had the algae myself so I can't really recommend one methond~

let's see what other members have to say. I think there are some posts anout bba in the freshwater aquariums section. you might want to read those as well...
 

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I agree it is likely some type of brush algae. This is actually a red algae, but in most tanks it looks dark brown or black, sometimes very dark green/grayish. I have fought this algae several times, and it is now under control.

It is due to the light and/or nutrients being more than what the plants can utilize. Unfortunately it will continue to spread over every plant leaf until the plants are all dead, if not checked.

The way to deal with it is to create a balance between light and nutrients. From what you've told us, you have a T5 fluorescent tube over the tank. Is this HO or NO? And what is the Kelvin rating?

On the nutrients, what is the GH of your source water? And how frequent are water changes, and how much volume?

Byron.
 

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Discussion Starter · #8 ·
It's a T8, my mistake, 8000 Kelvin, HO. I do weekly 25% water changes so 5 gallons per week get replaced. As far as GH, I'd have to contact the local water authority.
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Is you tank a 20 high or long? You likely have a lot of light either way, but certainly too much for a 20L, which isn't a deep tank. I'd drop the photoperiod to 8 hours/day at a minimum no matter what. You say "about" 10 hours. If you don't use one already, pick up a light timer!
 

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I agree. But I'm a bit confused over the light...T8 does not come in HO, it is basic fluorescent. T5 has HO (high output) and NO (normal output, which is roughly equal to the same length T8 tube). Anyway, reduce the light down to 8 hours.

I'd still want to know the GH though, as this is a source for the "hard" minerals that are insufficient in Flourish. Part of that balance again.

Byron.
 

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Discussion Starter · #11 ·
Its a twenty gallon high. I'm sorry about not being more specific about the bulb specs as it came with the hood and the box was not very forthcoming as far as info on said bulb but it is a T8. I'm almost certain it's hard water as there are lots of minerals in the water and the water source has minerals deposits nearby but don't know how hard. I will try to contact the water and sewage authority tomorrow to get the specifics. Should I add more plants to help with excess nutrients in the water?
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Its a twenty gallon high. I'm sorry about not being more specific about the bulb specs as it came with the hood and the box was not very forthcoming as far as info on said bulb but it is a T8. I'm almost certain it's hard water as there are lots of minerals in the water and the water source has minerals deposits nearby but don't know how hard. I will try to contact the water and sewage authority tomorrow to get the specifics. Should I add more plants to help with excess nutrients in the water?
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More plants will always improve things, as algae will have to struggle more with the competition. But this only works so far, if something is out of balance. And, several of the named plants are stem plants which are fast growing. Aside from the algae, are they doing well?

In summary, the light is a T8 tube, over a 20g high (normal) tank, on 10 hours. Flourish Comp added once a week. And we'll assume the GH is sufficient for the hard minerals.

If the water is quite hard, algae will be more likely. And with the light on 10 hours, some other nutrient might be missing. I would still suggest reducing the light duration to 8 hours (with a timer). Give this a few weeks. This algae should stop increasing, that is the key; what is there will not go away, but if it doesn't spread, you've solved the issue.

Byron.
 

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Discussion Starter · #13 ·
Thank you Byron for your input. I will purchase a timer within the next day or two. I am also in the process of getting more plants, including fast growing plants.
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