Spot algae growth on plants and glass

["Pete" <peteal at sympatico_ca>]

Hello, can anyone give me tips on how to limit or stop (I would be so happy)
spot algae.
It not very bad, I only scrape the glass once a week because I like a
perfectly clear view of  the tank but my slower growing plants get wrecked.
I have an Anubias that is growing nicely but because it doesn't drop older
leaves or grows quickly where you trim the tops and replant the older leaves
don't look nice. BTW is it ok to cut the stem of the anubis to remove the
older ends?

I use PMDD and Master grow and have a DIY CO2 into my canister filter which
keeps the PH down to 6.6.
Nitrates, Phospates, iron are all at low levels but more than just
detectable (any lower phospates and my Cabomba went stagnent).  If anything
I find more iron inceases the algae than does an excess of phospates.
Lighting is with MH (350 total for 90 Gal). Soil is gravel with laterite.
Medium fish load.

I'v seen those spot algae free tanks on the net (and at the Big Al's
aquarium store) and want so know if I can get my tank that way :)

Thanks in adv.
Pete.