That critter is nothing to worry about, may even be a preditor. The 6.6-6.8 ph is MONEY!! You can bump feeds up to 6.3-6.4 and be right in the wheelhouse!! As the media dries and plant eats the ph Should rise up like this in a functioning #4 soil system. Yes they are hungry for sure, keep at the feeds and if you want, hit them with a foliar that will green them up!! 5 ml Pegasus , 5 ml Ful-power ph to 6.2, if the ppms are under 350 you can throw in some Poseidon to get some of the many benefits of kelp foliars!! But can always do the kelp foliar on another day, with perhaps Kraken instead of Pegasus. Just keep it simple and try to work in a foliar twice a week if you want to try them, Hygeia is good too, any yucca or aloe to act as a wetting agent.......spray right when they wake up, by the end of the day you will notice a nice Kelly green/emerald green leaf color come on from the pegasus!! And sometimes those mutations produce extra dank phenos, some don't....LOL.....just let it play out!!