How to Fertilize Slack's sundew?
Balanced perennial feed every four weeks from spring through summer

Slack's sundew · Drosera slackii
Under glass grow in a mix of equal parts moss peat or fertiliser-free peat substitute and sand, in full light, although may need shading from hot midday sun in summer. The compost should be kept continually moist to wet during the growing season by standing the container in a tray of lime-free water, such as rainwater or Reverse Osmosis water. Keep just moist during the winter and do not stand the plants in water. Do not apply fertiliser at all through the year. Minimum temperatures should be no lower than 5C in the winter. In lower temperatures the plant may die back to the roots, but sometimes regenerates again in the spring.
Balanced perennial feed every four weeks from spring through summer