Red Algae

[Pabs311]

ok so i've been noticing some red algae growing in my tank. most prominently on my plastic plants and plastic filter tube. i dunno what causing this, i do regular water changes of 25% once a week, sometimes 50% depending on water clarity and water stats. what can i do to stop this from occuring? thanks

 

[aaronnorth]

it is black brush alae, but in high KH waters it sometimes turns red as it uses carbonates as a source of carbon from the water.
It is caused by fluctuating CO2 levels & poor circulation.

Remove as much as possible and hopfully it wont return.

meanwhiule can you answer these questions please:

tanks size?
wattage of lighting and diamter (T5/ T8 etc)
filter?
powerheads?

Thanks