Metal Halides and Hair Algeas


New member
I'm looking to find the best brand/price on bulbs for my light, It's made by hamilton, It has 2x 110w True Actinic and 2x 175w MH w/ a pulse start ballast. I am tring to avoid cheap ebay bulbs, but I'm trying to be cheap. Catch 22, What?

I bought it used at a LFS, and although it looks good I think the bulbs need to be replaced I've had it 4 mos. & dont know how long the bulbs were in use prior to that.

I just set it up on a new 75gal 2.5 weeks ago and I am seeing the begginings of a hair algea problem. I think my parameters are good so I've moved on to blaming the bulbs. I currently have the light on for a 7 hour period.

Params I tested this Morning

PH: 8.0-8.2
Ammonia: 0
Nitrite: 0
Nitrate: 10 or less
Phosphate: 0
Calcium: 440

I am using RO.



Tang Salad

Algae skeptic
If you're getting hair algae, then the bulbs can only be partly to blame. There must also be nutrients for the algae to grow.

But, what is the Kelvin rating of the bulbs you use now?


New member
Not Much, 15-20 Hermits, I have some turbo snails in route.its a new setup so I havent added any fish either.

What do you recommend for a clean up crew in a 75 with 100-150 pounds of live rock?

Craig Lambert

Premium Member
Excess nutrients cause hair algae, not bulbs. nikonosis is referring to your Alkalinity level. If you don't have an alkalinity test kit you need to get one. (The Salifert kit is excellent). Your Alk should be in the range of 7-11dKH. If it is low it easier for the algae to grow, although high alk will not stop it if excess nutrients are present.

Are you using RODI water? You said RO, so I'm wondering what the source is. Your tank is new so some algae is to be expected. I would cut the lighting period since there are no corals present yet.

How much flow is there in the setup?