Jef79answered grow question 5 years ago Hello.. Hope you are well.. Tbh it just looks like chelated nutes that have formed together around roots and bonded.. U can see clearly seh has sum lovely white roots growing thru so ur levels must b within the safe range for her.. Try simply rinsing them off very gently with room temp ph'd water.. Check my diary from this wks shiskaberry 2nd round to see how build ups can start, if unattended, they can and will create problems for ur girls.. A regular weekly change of nutes will keep her fresh and a clean of sides and equipment will also help stop any nasties building up in ur res.. Stay safe n gud luck with ur girls .. 👍🍀