Hair Algae Question

[Channti]

I've got some hair algae in my 15 gallon planted tank. I'm not too concerned about it, as I understand that it's not harmful to fish, but I'm just curious as to what the causes of it are.

This tank is rather unconventional, as it's lighting consists of two CFL bulbs, totalling about 11watts of light, and the tank itself isn't dosed with anything. The tank is overstocked (7 female bettas, 6 corydoras, 2 otocinclus affinis), and heavily planted (Hygro. polysperma, amazon sword, crypt. lutea, crypt. undulata, crypt. wendtii, marimo moss ball, java fern).

Filtration on the tank is an Elite Hush 20.

The hair algae appears primarily on the Amazon Sword plant, which is in a corner, far from the filter. I've noticed that this is a bit of a "dead zone" in the tank when the hygrophila gets within an inch of the tank rim, as the hygro is planted in front of the filter. Could hair algae be caused by lack of water movement?

If it's cause is a lack of water movement, what options do I have in a tank this size for increasing water movement besides buying a larger filter?

 

[ian]

I think you may have hit the nail on the head. Along with a bit of low C02 and flow, i think this is probably why you're getting hair algae. Have you tries moving the filter more centrally in the tank, i see it has 2 outlets. Hopefully if it was central, it would spread the flow evenly. You could always add another HOB. heres a neat little filter at good price.