Green Hair Algae problem

[mpdharley]

I'm having a problem with green hair algae in my 330g tank. Based on the water tests, I can't figure out why I'm having the

Everything in the tank was moved from an established (4 year old) 125 gallon tank (with no problems), including 175 gallons of water. I used water from the 125 (when doing water changes) to start the filling of the new tank.

The stats on the tank:

Tank: 330 (approx) gallons (6' x 4' x 2'), everything moved into it just before Christmas, 2006.

Occupants: Besides, LPS, SPS and soft corals, 5 fish (foxface, green chromis, coral beauty, purple tang, mandarin), crabs and snails.

Live Rock: About 300lbs with half of it coming straight from the old 125, the remaining was base rock or old live rock that was boiled.

Substrate: Sand, shallow bed (about 2 - 3 inches). Seeded with live sand from the original 125.

Lighting: 3 x 250 MH DE, XM 20ks. Lights on 12 hours

Fuge: 30+ gallons with Chaet, with good growth. The lights are for 12 hours, off cycle from the tank. Sand bed is about 7 inches, seeded with live sand from the fuge on the original 125g tank.

Skimmer ASM G4x, good skimmate generation (empty about once a week)

Ozone: 500mg/hr Enaly generator. I've had some issues getting the generator to get the ORP above 320. I believe I've discovered the issue, which is back pressure from the pressurized ozone reactor. The generator couldn't compete. I believe I've solved this issue.

Feeding: 3 times a week, 1 cube of formula two or home made (fresh fish, chopped), soaked in Selco. Seaweed, on a clip about 3 times a week.

Water movement: Main return, Dart pump, running full. Closed loop: Dart pump (running full), OM 4way. I haven't found any real dead spots in the tank.

Water Changes: I was changing approximately 80 gallons a month and have since switched to about 40 gallons a week (last 3 weeks).

Every other water change, I remove the green hair algae that is on the sand and the algae that is easily sucked up from the rock (I haven't done much scrubbing).

Water Parameters:

Temp: 80
Salinity 1.026 (refractometer)
Ph: 8.0 (recently calibrated probe)
ORP: 323 (ORP is coming up)
Alk: 8.4
Calcium: 430
Phosphates: 0
Nitrates: 0
Nitrites: 0
Ammonia: 0

Any ideas on what is feeding the green hair algae?

[Bob Betzel]

I had been fighting the green hair algae problem for about a year and tried everything anyone could tell me and nothing worked until both of my VHO ballasts blew out at the same time. I was at the point of totally breaking the tank down. I fiddled around trying to get my lights to work for 2 weeks all the time concerned the clam I had was going to kick the bucket as I only had one low wattage tube on the aquarium. I finally sent them to ice cap for repair. By going from 630 watts to ~30 watts for almost a month my algae problem was cured. My problem was I guess old tank syndrome (set up for 12 years) so this cure may not be feasible for you but I would now always think about lighting when it comes to algae.

[mpdharley]

I've thought about cutting back my lights, or maybe increasing the period on my fuge. My only concern with cutting back the main lights are the corals in the tank.

[mpdharley]

I want to thank everyone/anyone who has posted or does post. I may not reply to every post, but I am reading them and I am grateful to all suggestions/comments.

Mike