Problem with new tank

I have recently set up a 55gal planted tank and am now having trouble with black
brushlike algae. It has covered many leaves of crypts and pygmy chain swords.
The fish store guy recommended I use a phosphate remover compound. Will that
help? Also plant growth has been slow.

Substrate: Duplarit & gravel
Filter: Penguin 300. Sponge in first chamber hopefully for bacteria growth. and
activated carbon in second chamber
Lighting: 2-4ft fluorescents (came with light hood) and 1-3ft triton bulb
Fish: 7-oto's, 4 SAE, 1-cory cat (plus some annoying pond snails)
Setup: 9/15/96
Plants: 2-amazon swords, 4-crypt wenditti, 4 dwarf saggitaria, 7 pygmy chain
swords, 8-stalks of pennywort, 12-stalks of cabomba
pH: Alkaline 7.6-7.8
Temperature: 76F
Water change: 5 gallons per week

Tom Heal
Homemade CO2 just bubbling into water via airstone.

Any ideas on how to control this algae and to improve plant growth.