am I fertilizing too little for 4wpg?

Nearly half a year ago I upgraded to 4 wpg (yah I know, holy crap am I
nuts?) I noticed an increase of algae proliferation. Mostly it (green hard
algae) starts to collect on the glass on the front (Probably because now I
have one of the bulbs closer to the front). My anubias MUST hide under other
plants to grow without algae because of the high lighting. One bush of
plants I have been cropping a lot of leaves off that have spot algae. I know
4wpg is a huge challenge to maintain a balanced aquarium but...any
suggestions?

Specs:
- 15 gallon wide (12" high)
- approx. 24-28ppm C02
- Fertilizing 1/8 tsp (0.6ml) KNO3 every other day and 3/4 tsp (3.6ml) of
traces on the off-days (I stopped doing P...but should I start?)
- Perform a 50% water change every week (scrape glass, remove algae infested
leaves)
- 3 SAEs, 4 otosinclus, 8 harlequin rasboras, some clowns & cats
- 12 hrs/day of 4wpg light with acrylic mirrored reflector (three 24" bulbs
spaced evenly)
- huge amount of plant proliferation, lots of fast growing hygrophila
polysperma, hygrophila polysperma 'Rosanervig', rotala indica, ludwigia
repens (extremely red, really no green on this plant...possibly a sign that
I need more nitrate?...after the light increase this reddened immensely),
lush and fast growing java fern, hidden anubias growing on driftwood (did
much better when I had 2.66 wpg), a huge forest of crypt that sprouts
everywhere!, bacopa australis that is getting algae on lots of the leaves
but growing fast.

Opinions? Thanx!!

Dave