Congratulations on your 2nd grow!! You tent is packed from wall to wall and you did a great job so far.
About foxtail and density: welcome to the world of genetic and pheno hunting!
Most of the times, when you buy cannabis from a dispensary or the black market, expect that the growers did some work and research to bring you an exciting product. Reason for that is genetic and phenotype. All germinated seeds will grow a different plant sharing some characteristic of their parents. Finding the one that grows hard buds, with dank smell, awesome colour, high THC, high resistance to stress, heavy yielder, great effects, require some research, work, or sometimes Luck.
It is normal to get the results you get, despite a few tricks can improve your harvest.
1- start with premium genetics. Read reviews, do some research, talk to other growers.
2- strong light. You are a little bit on the limit with your setup. 450w would be just fine for a 4x4. Growing in a 5x5 in much more square foot to cover (16sqft vs 25...) You might want to get an other light.
3- following a VPD chart.
4- having proper air exchange, airflow, (CO2 supplement, in a closed setup)
5- plants health, avoiding any deficiency or nutrient excess
6- having an even canopy, using training techniques.
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