Nello zucchero or Nell zucchero

Hello .iI am trying to learn Italian by on my own/ by myself and I can't understand something .
I saw these following sentences:
"nello zucchero" and "l'acqua e nel zucchero"
I can understand nello zucchero (in+lo) nello zucchero but I can't understand how Nell zucchero is correct .
I tried to found meanings but I didn't .
Thank you in advanced

You are right: Nello is in+lo that means inside 'dentro'; l'acqua e lo zucchero is correct otherwise it is meaningless.