How does hair algae spread?

[MikeP]

Hi all, it's been far to long since I posted here. I've been very busy for the last several months. Anyways I have a friend whose wife has a salt water tank and she is taking it down. This friend of mine said I could have everything and all I had to do was pick it up. I went there tonight wanting to just take a look to see if I wanted to take the stuff but when I showed up she had everything in buckets ready to go. Now I have about 50 pounds of live rock covered on some type of hair algae (this is exactly why I told him I wanted to see the set up first, I would have told them I didn't have room if I'd of know it had all this algae). Anyway I managed to fit everything in the sump. I have never had any hair algae before so I don't know that much about it other than it can me a real PITA. I plan to buy something to eat it and then put the rock in the display tank when it's 'all cleaned up'. After I got everything in the sump I started thinking that maybe hair algae has spores and my display tank may start to get a hair algae outbreak anyway. So I need to know how it spreads (contact only or spores or what?). I've had a algae free tank from a very long time and I really want to keep it that way.

Any info would be great, thanks.

[Myka]

It will spread by pieces getting dislodged, and reattaching somewhere else. So it's quite possible that it could migrate up to your display. The HA on the rocks you got is likely from a tank with excess nutrients like phosphates and nitrates which the new rock WILL leach into your water, which could cause your system to have high nutrients, and therefore become a good breeding ground for HA.

I would suggest you remove the rock from your sump, and put it into a Rubbermaid container with saltwater, a lid, a heater, and a good powerhead. Do weekly 100% waterchanges siphoning out all detritus. Keep it with good flow in the dark until all the HA is gone (this will probably take a couple months at least). Once the HA is visibly gone, test the water for phosphates and nitrates using good test kits like Elos or Salifert right before you do your weekly waterchange. Once nitrates and phosphates are both undetectable you can use the rock. You're looking at least 2-3 months. This process is called "cooking" live rock.