Just from experience : you may want to consider hanging MH light that close to water surface. 3 x 150W of metal halide is already serious light over your tank size, even though many people may not consider so, but let me assure you to hang them a bit higher (probably twice of current height). Excessive MH light (usually from hanging too low) may cause problems to your plants.
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700gal sunken garden. Screened sunlight and 1 x 400W MH. CO2 injection. Wonder-Gro series ferts.
260gal planted open top tank#1. 3 x 150W MH lighting+ 4 x 40W T12. CO2 injection. Wonder-Gro series ferts.
260gal planted open top tank #2. 3 x 150W MH lighting + 4 x 30W T5. CO2 injection. Wonder-Gro series ferts.
Wonder-Gro series ferts (available @GLA)
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