Algae identification and cure needed

Ian H

Guru Class Expert
Jan 24, 2005
Shipley, West Yorkshire, UK
A type of algae new to me has decided to attach itself to my Amazon sword plant. I don't have any photo's so I'll try to describe it.

It is charcoal grey in colour and about 0.5cm in height, growing in patches/tufts mainly on the stem and leaf margins of the older leaves. The plant is growing well and it doesn't affect the new leaves at all. No other plants are affected although a small amount attached itself to a powerhead.

I am pruning the affected plant to remove what I can. Recently I let my nitrate levels reach zero and I suspect this was possibly the cause.

Could someone try to identify the strain and advise on it's erradication please.


Tom Barr

Staff member
Jan 23, 2005
Re: Algae identification and cure needed

Add KNO3 at 1/4 teaspoon 80 liters at least once a week, more if you have high light /CO2/ good plant biomass.

Add more CO2, trim off what's there. I promise the sword will grow more leaves:)

Tom Barr


Junior Poster
Jan 24, 2005
Halesowen, England
Re: Algae identification and cure needed

I also have a type of algae I don't recognise. It's green, approx half centimeter long, single stem, base attached to leaf and at "head" end it sprouts news stems, in a regular fashion around the "head". (imagine a pitchfork with two heads at right angles to each other) It appears as solitary stems on different plants.
Does this indicate a deficiency or excess of anything?
Regards Martin