The effect of Storm (fertilizer with 3% growth regulators from Sargassum and A. nodosum algae and 6% organic N) on germination parameters and seedling vigor in rice was examined in seed from San Andrea cultivar produced in 2017 and 2018, treated with three concentrations: 0.1%, 0.5% and 2.5% against a control (no fertilizer added). Germination energy, total germination, germination speed, seedling (root, shoot and total) length and dry weight and vigor indexes (I and II) were examined. The results were statistically evaluated by two-way ANOVA and LSD test. The total germination (94.38% to 96.75%) was not affected by the treatments, while the germination energy and the germination speed were significantly negatively affected by the 2.5% treatment- 83.00% and 21.53 accordingly against 90.63% and 23.94 in the control). All Storm treatments significantly increased the seedling length. With the increase in concentration, the root length decreased while the shoot length increased. Even thought all of the Storm treatments significantly increased the Vigor index I (1587.44 to 1644.75) and Vigor index II (35265.38 to 37753.75) compared to the control (1362.07 and 29984.50 respectively), they affected the seedling development differently. The 2.5% treatment negatively affected the development of the seedling, as promoted increased development of the seedling shoot, but inhibited the development of the root. Best results were obtained with 0.1% concentration, as it significantly promoted both the root and shoot development and resulted in significantly higher index I, index II, shoot, root and total seedling length compared to the control. With this treatment were obtained the longest root (7.98 cm), the highest root dry weight (3.89 mg) and the highest root volume (50 μL) in the trial.