I have been quite successful at growing hair algae in my tank, though not quite as successful at getting rid of it. I've learned a lot about it though in the process. I agree with both Ace and CJ. A phosphate or nitrate reading of 0 probably just means the algae is using up the nutrients as fast as they're being generated. Silicates can also fuel algae growth, although usually you will see a diatom bloom with high silicates. Another thing to check is your lights. Old lights will shift their spectrum to one that is more favorable for algae growth. If your bulbs are more than a year old I would replace them.
The trick to getting rid of the algae is to eliminate their food source. To do that you need to figure out where it's coming from. A couple of culprits could be either bio-balls or filter bags if you have them. I change out my filter bags every day now (OK, sometimes every 2 days). These are traps for organic matter that decompose and release nutrients back into the tank. Also check up on your clean-up crew. I don't know how large your tank is, but in larger tanks it is easy to lose track of them. After a while their numbers can become depleted and they can't clean up your tank quick enough. You may need to replenish them. Also, pull out as much algae as you can each day. This is a way to export nutrients. When the algae dies in your tank, it release all the nutrients they took up right back into the tank, so you get a viscous cycle. I'm experimenting with dosing with alcohol in my tank, but it's too early for me to draw conclusions on whether or not it is helping (although signs are encouraging).
The trick to getting rid of the algae is to eliminate their food source. To do that you need to figure out where it's coming from. A couple of culprits could be either bio-balls or filter bags if you have them. I change out my filter bags every day now (OK, sometimes every 2 days). These are traps for organic matter that decompose and release nutrients back into the tank. Also check up on your clean-up crew. I don't know how large your tank is, but in larger tanks it is easy to lose track of them. After a while their numbers can become depleted and they can't clean up your tank quick enough. You may need to replenish them. Also, pull out as much algae as you can each day. This is a way to export nutrients. When the algae dies in your tank, it release all the nutrients they took up right back into the tank, so you get a viscous cycle. I'm experimenting with dosing with alcohol in my tank, but it's too early for me to draw conclusions on whether or not it is helping (although signs are encouraging).
