I'd say go for it, throw the light back up to 18 or 19/5
Btw, amazing plants for all the abuse you've described haha! Have ya considered mixing in some Neem meal in with the medium in the future? I'm in soil though, but I haven't seen a bug since starting to mix in the Neem meal from neemresource.com and no reason it wouldn't mix in just fine into coco / perlite, I don't think. Might save ya having to drench with the h2o2