I can't figure out why I have low par on 400w mh. (Fixture 18 in above water and reading 150 just below the water) I bought a new bulb and still low par. I possibly thought it was my par meter but confirmed that it is reading correctly. Then I thought it could of been the ballast so purchased new electronic ballast and still low par. I ran the new bulb on the old ballast for 1 week but wouldn't think that would ruin the bulb. Any ideas would be appreciated. This is very frustrating. Thanks
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