What Is Causing My Bba?

[marieukxx]

I have 3 tanks, two pllanted and one fake. The planted tanks are fine but in my fake tank which has been set up for about 4 years I've noticed a very small amount of black hairy algae. It's only on one ornament which is a fake log thing. I first noticed it a few months ago and scrub the orament in the places it appears each week. Just now I noticed it's growing again in the same places. It's only on this one log.
 
What can cause it? I have the lights on about 6 hours a day and all tests are normal. I am pretty sure it is Black Brush Algae from pictures I've looked at online.
 
How do I get rid of it? Is it just a case of scrubbing it off each time? It seemed to go away for a few weeks recently but today I've noticed it again.

 

[ian_m]

http/theplantedtank.co.uk/algae.htm

 

[SO19Firearms]

http/theplantedtank.co.uk/algae.htm

 
That won't count if it's the fake tank with the problem unfortunately. In this case I'd have to go with removing all sources of food for the algae along with low light.
 
IMO

 

[zanda]

how often u do water changes?
tap water or RO water?

i had hairy algae in my 60l, 
the easy way to find source of algae, dont fight with it.
do 50% weekly water changes, max 10h light, good filter.
Try seachem prime to remove all organic waste from water.
on the end i lost all my plants and i start deep cleaning.

 

[snazy]

What can cause it? I have the lights on about 6 hours a day and all tests are normal. I am pretty sure it is Black Brush Algae from pictures I've looked at online.
 

 
Do you have any types of stones in the tank?