jduprie wrote:

Hi folks,
I'm in the process of setting up a new tank (125 Gal, fresh, planted),
and was wondering if hiogh iron levels will be a problem. The current level
is .640 mg/L (yes thats not a typo). Ph is 7.8, and hardness is 59 (Calcium
carbonate). The only thing that seems out of whack is the iron... I have a
water softener (ionic collumn) that brings the iron levels way down, so I
*could* just use the softened water, but its a lot easier (plumbing wise) to
use the untreated water......

High iron can be a contributor to green thread algae. When my tank is nutrient
limited (low in Nitrate or traces), I can induce a bloom of the stuff by
increasing Iron to 0.2ppm. But when my tank is not nutrient limited, the algae
is much less likely to appear, even with high iron.