A 60-day experimental trial was conducted to investigate the effect of different dosages of potassium supplementation on Spinacia oleracea L. and Pangasianodon hypophthalmus in an aquaponic system. The system consisted of 168 l rectangular fish tanks (0.78 × 0.54 × 0.40 m) with 100 l water volume stocked with P. hypophthalmus at 2.8 kg m^-3 and Nutrient Film Technique (NFT) hydroponics with spinach at 28 plants m^-2. Four dosages of potassium viz., 90, 120, 150, and 180 mg l^-1 were assigned as T1, T2, T3, and T4 and compared with control C (0 mg l^-1) to determine the most efficient potassium dosage for the aquaponic system. The physico-chemical parameters and nutrient dynamics were within the permissible range with no marked variation between the control and treatments. The spinach was harvested twice. The first harvest before potassium supplementation showed no significant difference. In the second harvest, the potassium supplementation had a significant (P < 0.05) effect on the yield of spinach with the highest yield obtained in T4 (280.07 ± 2.26 g) followed by T3 (277.57 ± 3.02 g), T2 (265.07 ± 4.61 g), T1 (256.80 ± 4.79 g) and C (217.83 ± 4.20 g). The yield showed no significant difference in T4 and T3, and T2 and T1. The mean body weight of fish at harvest was insignificant (P > 0.05) and followed the order: C (33.23 ± 0.52 g)>T1 (33.07 ± 0.45 g)>T2 (32.94 ± 0.40 g)>T3 (32.23 ± 0.37 g)>T4 (32.15 ± 0.35 g). The plant analysis revealed that potassium supplementation triggered the nutrient synergism resulting in higher nitrogen, potassium, phosphorus, iron, and sulfur content in T4 followed by T3, T2, T1, and C. The evaluation of the physiological response of P. hypophthalmus showed higher plasma glucose in T4. Considering the water quality parameters, fish growth, physiological response, spinach yield, and nutrient content, a dose of 150 mg l^-1 K⁺ (T3) could be recommended as an optimum potassium dosage for P. hypophthalmus-Spinacia oleracea L. aquaponic system.

进行了一项为期 60 天的实验试验，以研究不同剂量的钾补充剂对鱼菜系统中Spinacia oleracea L. 和Pangasianodon hypophthalmus的影响。该系统由 168 升矩形鱼缸 (0.78 × 0.54 × 0.40 m) 和 100 升水量组成，其中装有2.8 kg m ^{-3 的下}眼线虫和 28 株菠菜的营养膜技术 (NFT) 水培法，m ^-2。四种剂量的钾即。、 90、120、150 和 180 mg l ^-1被指定为 T1、T2、T3 和 T4，并与对照 C（0 mg l ^-1) 以确定鱼菜共生系统最有效的钾剂量。理化参数和营养动态在允许范围内，对照和处理之间没有显着变化。菠菜收获了两次。补钾前的第一次收获没有显着差异。在第二次收获中，补钾对菠菜产量有显着（P < 0.05）影响，T4 产量最高（280.07 ± 2.26 g），其次是 T3（277.57 ± 3.02 g），T2（265.07 ± 4.61） g)、T1 (256.80 ± 4.79 g) 和 C (217.83 ± 4.20 g)。T4 和 T3 以及 T2 和 T1 的产量没有显着差异。收获时鱼的平均体重不显着（P > 0.05），顺序为：C（33.23±0.52g）>T1（33.07±0.45g）>T2（32.94±0.40g）> T3(32.23±0.37g)>T4(32.15±0.35g)。植物分析表明，补钾引发养分协同作用，导致 T4 中氮、钾、磷、铁和硫含量较高，其次是 T3、T2、T1 和 C。P. hypophthalmus在 T4 中显示出较高的血浆葡萄糖。考虑到水质参数、鱼类生长、生理反应、菠菜产量和营养成分，建议使用 150 mg l ^-1 K ⁺ (T3) 作为P. hypophthalmus - Spinacia oleracea L的最佳钾剂量。鱼菜共生系统。