They sell circle tomato cages that may fit better with grow buckets for $5 bucks apiece.
Heres a J.Lambsbread.
Its in FFOF soil and its too hot for it. When I t/p them from 1's to 3's they will go into 50% HappyFrog and 50% Chunky Perlite.
You can see the tips curling down which indicates too much Nitrogen~
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I often have problems growing real sativas in soil mixes with too much FFOF in them but have seen others grow them successfully in 100% FFOF which always baffles me.