I read somewhere that hillstream loaches do best (long term) on a diet consisting of brown algaes. I've tried various wafers and stick-ons, but the loach won't touch them. It avoids them like obstacles while polishing the glass and/or rocks.
So far I haven't had any trouble keeping brown algae flourishing in the tank. Its not out of control, but there is certainly enough for the loach and snails to feast upon. It grows on the rockwork and glass, but seems to avoid the plants. I guess it looks like green spot algae, but it is brown and doesn't necessarily grow in patches.
The tank has a decent current, high lighting (3 wpg over shallow water), and a cool temperature (65 F). Perhaps the algae flourishes at cooler temperatures?
I posted this question because I am concerned that this algae will die off, leaving the tank open to BGA invasion. I've noticed a slow and steady trend to this effect--more green, less brown. I hope to prevent the take-over for the sake of my plants and loach.
Do different algaes flourish with different excess nutrients? For example, will one algae flourish if nitrates are in excess but fair poorly if nitrates are lacking but only light is in abundance?