Swords decay and dying

[johnnynothumb]

I have newly planted 125 gal freshwater tank and am having problem with holes and decay in the leaves on the swords
mon,wed,fri i dose with potassium,nitrogen,iron and organic carbon. It is on 3.8 bubbles a sec of co2 14hrs a day,
Ph 6.8
kh 5
gh 10
no2 2 ppm
no3 20ppm
phos. .25
Temp 79*
t8 6500k lighting
the gavel bed is a mix of 3/16-3/8 gravel and florite
i dose with equilibrium with water changes
this tank is 4 months old but it should be responding better than this. please help