No less nitro ... they seem to have stored plenty .
What lights you running. ?
More light means More Buds.
Buds will gain its weight and bulk between week 5 to 8 .
As long as it is being fed properly and getting max light , they will swell.
A light air oscillating over canopy will exchange oxygen and CO2 in environment, even at lights out.
They look good just don’t give them too much nitro .
One of the symptoms of overnuted nitro ..... IS smaller buds.