# Black spots on plant leaves



## saugata (Nov 30, 2005)

Hi! All,

My tank is 90g and is about 6 months old Its densely planted. For the past few days I am seeing blackening of the tips of Windelow Java Fern and also black spots on other Java Fern leaves.

I can also see green algae like deposists on the plants having big leaves. 

What are the causes of these and how can I tackle them?

Otherwise plants are growing well and I am having to do pruning every week or so.


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## Digsy (Mar 4, 2006)

Saugata, I have that same problem with all my java ferns so, I'd be interested to see what kinds of solutions you get! Sorry I don't have any answers myself...


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## spypet (Sep 15, 2006)

sounds like your nitrates are too high.

I would consider in this order;
stop dosing NO3
do a gravel vacuum,
50% water change, (continue weekly)
rinse your filter media
brush out your filter hoses,
cut your fish feeding by half,
reduce your fish population,
us a nitrate sponge media.

whatever hair algae on your leaves may need to be pruned away. in addition the plants may need to be removed, then do a 20:1 water:bleach dipped for 1-minute, then rinsed and soaked well with some dechlor to be sure all bleach is gone before replanting. do the same to any plastic parts in your tank water.
the black algae should go away on it's own once you get your nitrates under control by following some or all of the suggestions outlined above.

many java lace ferns are naturally black at their base.


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## saugata (Nov 30, 2005)

Thanks a ton Spypet for your reply. The top portion of the leaves of the Java Windelow is turning black. Well with regard to my dosing schedule, this is what I am following:-

After weekly w/c I dose - 

15 mls of KNO3 (stock soln. of 8tb spoons in 400 mls of distilled water)

3 mls of KH2PO4 (stock soln. of 2 tb spoons in 400 mls of distilled water)

3 mls of Traces


I repeat the same dosing on the 4th day.

I use pressurised CO2 and use a reactor to dissolve it in water. Light is 5 nos of 6500 K PL lights & 3 nos of 8000 K PL lights @ 12 hrs.

Any other thing I need to do? By the way, this blackening has started happening only recently. Prior to it the Windelow was growing quite well. I am also having the problem of GDA on the glass walls which I am trying to tackle by not cleaning the glass for a month or so. SO that the GDA completes its life cycle and falls off the glass on its own.


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## Digsy (Mar 4, 2006)

Saugata, are you getting black spots throughout the leaf or on the edges? I'm literally getting little black spots throughout the leaves. I know nitrates are not the issue in my tank as I have extreme difficulty keeping nitrates up.


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## saugata (Nov 30, 2005)

Thanks Spynet. I also thought so i.e., about the Nitrates being too high. Will do as per your advice.

But with regard to alage on the big leaves, I don't think it is hair alage. It is more like a thin green layer which will form on some of the leaves. I can also see some of the fishes viz., SAEs, American Flag Fish trying to munch on this algae growths. What can these growths be?


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## saugata (Nov 30, 2005)

@ Digsy,

The blackening starts from the tip and then slowly spreads out. Its is not plantlets. That I am sure of.


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## spypet (Sep 15, 2006)

Digsy; brown spots are usually from a lack of nutrition, so you may have the opposite problem saug has. get something like seachem's flourish tablets and put one under the base of the spotted java lace fern. that may not help in case nutrition is not you problem, but it won't hurt either.


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