Woodleysgrow

Growth is always quite slow untill the roots reach the water . All but 1plant have now reached the water. I expect the real growth to start now. Been having issues with PH It jumps every day from 5.8 - 8.4 . We're not sure of the problem yet but we believe its the residue on all the plastic which has left a white coating on the inside of all the buckets. Going to be doing another water change and try clean this white coating off. Hopefully PH will go stable eventually. This is our only issue at the moment Im just Adding PH down every day but this isnt ideal. Its not the clay pebbles as i popped some into a pot and checked to see if the PH rised and it didnt. Must be this white coating thats doing it. Any Ideas id really appreciate the input.