In the hydroponics, foliar application of K, Mg and Zn increased fruit number and yield of plants, but B and Cu decreased them compared to control treatments. Castro et al. (2006) found that irrigation with fish effluent enhanced tomato fruit number and productivity in the first three analyzed harvest periods. However, the increase in fruit number in treatments that received fish effluent resulted in lower mean fruit weight. They found that even with reduction on fruit mean weight, the increase in fruit number was enough to elevate the total productivity. Prinsloo and Schoonbee (1987) also observed an increase in tomato yield from 64.5 to 95.8 t ha−1 when plants were irrigated with fish effluent in comparison with plants which were irrigated with well wate