Here's what I would do if it were me (hint/hint). If you can change your res...change it then take number to 1000. Check in 24 hours.....I bet the beasts will have the number down. If the problem IS that....they should start to look better immediately but you MUST keep the number up.

If you can't change res....add 100-150 ppm of Pro Bloom.....check number and condiition of plant in 24 hours...(of course you are ALWAYS watching your ph)