My 20 gallon recently had a cycle crash, and since then I have had an absolute explosion of hair algae growth, it's festooning my plants and everything in the tank! Now that I think back on it, my 50 gal had a lot of hair algae before it cycled too. (Now it's just got a little on my filter out-takes as usual). Is excessive hair algae something that tends to happen in non-cycled tanks? And more importantly, will it go back to it's normal amount (a little here and there) after my tank gets cycled again? I scoop a bunch of it out every day, but I'll be darned if its not all back there by the next day. <_<

I'm not sure. My betta tank is having an inexplicable problem with hair algae. Nitrates and phosphate have both been tested and are low, tank has been cycled for months. And yet it gets bad hair algae. I put a crypt on each side instead of the fake plants, dunno if that will change much. It seems to like water movement, it only grows on the side with the filter, and in my other two tanks, the only hair algae is a couple strands on the filter output lip (like you mentioned for your 50g).