[DiverDude]

I have a bad Hair Algae (HA) issue as well and I've been doing a lot of research on this and the answer is annoyingly simple: you have conditions in your tank that are ideal for the growth of HA. What's that mean? It means you have light and food (excess nutrients).

Remove the food source and it will die.

Easier said than done !

The high points:

1. Remove as much algae as you can manually

2. You probably have elevated nitrate and phosphate levels. Consider doing several major water changes in close succession.

3. Ensure you have good, brisk flow to ALL parts of your tank

4. Consider reducing your photo period if practical. Check your lights and replace the bulbs if they are more than about 10 months old

5. Feed lightly

6. Hunt for any possible source for nitrates and or phosphates and remove them. Some common sources:
- dead livestock
- Using tap water instead of RO (RO water from the supermarket is NOT good)
- Low quality salt
- canister filters
- Frozen fish foods

Test your source water and your tank water. Realize that many test kits aren't sensitive enough for low level measurements and that you may get results showing zero (or very close to zero) levels of NO2, NO3 and PO4 but you actually have active 'generators' of these and the HA is feeding off it and giving false test results. The HA is *PROOF* that there are excess nutrients in the water, regardless of what any test says.

Be prepared for the long haul; this will not disappear overnight. Continue to feed lightly, run a good skimmer and do regular (weekly) water changes.

Running Phosban may also help but I can't comment on that -yet.

Good luck.