Martian and Lunar regolith is an attractive local source of minerals for extraterrestrial hydroponics and aeroponics systems. Plasma has also shown promise in managing water quality, including infectious diseases, and nutrient availability in the food producing systems on Earth. Here, we studied the effect of plasma treatment on the quality of water that was enriched with elements extracted from simulated Martian and Lunar regolith (SMR and SLR). Water was first exposed to either SMR or SLR, and then either treated with plasma or used directly to grow Medicago sativa and Brassica oleracea microgreens. When compared to non-treated counterpart, the use of plasma-treated SMR water increased root and shoot length for M. sativa by 12.5% and 5.9% respectively, while reducing these parameters for B. oleracea by 7.4% and 37.5%, respectively. For plasma treated SLR water, we observed an increase in root and shoot length for M. sativa, at 8.0% and 37.8%, respectively, while reporting a corresponding reduction of 48.2% in root length and an increase of 8.2% in shoot length for for B. oleracea. Plasma treatment of SLR water was found to increase the availability of 24Mg, 27Al, 31P, and 57Fe isotopes associated with improved plant growth in both alkaline and acidic conditions. However, in plasma treated SMR water, higher levels of isotopes of 66Zn and 111Cd were observed, which may adversely impact plant development, while reduced concentration of 27Al may affect nutrient availability and increased 60Ni and 65Cu may influence enzymatic processes, potentially causing stress or toxicity. These results suggest that plasma may be a promising tool for fine-tuning nutrient availability in water-based space agriculture systems where local minerals are used.