Lake poems with quality must be a magnet (9)
I believe the answer is:
lodestone
'a magnet' is the definition.
(lodestone is a kind of magnet)
'lake poems with quality' is the wordplay.
'lake' becomes 'l'.
'poems' becomes 'odes' (ode is a kind of poem).
'with' is a charade indicator (letters next to each other).
'quality' becomes 'tone' ('tone' can be a synonym of 'quality').
'l'+'odes'+'tone'='LODESTONE'
'must be' is the link.
(Other definitions for lodestone that I've seen before include "Natural magnetic ore" , "Mineral" , "attractive person" , "Naturally magnetic rock" , "focus of attention" .)