LAGUNA: FERTILIZER POND SPIKES/BULK 50/PK Plant Grow Fertilizer Pond Spikes PT-910 & PT-911 Laguna Plant Grow Once-A-Year Fertilizer Pond Spikes supply important nutrition to aquatic plants for one full year. The temperature-activated feeding sticks release nutrients only when plants need them most - at or above 50ºF (10ºC). Once activated, the spikes slowly release a well-balanced feeding formula that maximizes the size and color of all potted aquatic plants. Laguna Plant Grow Fertilizer Pond Spikes • For all potted aquatic plants. • Maximizes the size and color of aquatic plants. • Well-balanced feeding formula. • Low phosphorous, no adverse impact on water quality. • Contains no copper. • Non-toxic to fish and other aquatic life. • Temperature activated at 50ºF (10ºC). • Lasts one full year.