How do user reviews compare magnesium sulfate products for bath use?

I visited a gardening supply store to ask about potassium nitrate two days ago. I wanted something useful for improving plant growth and garden health. I also wanted to know which brands people trust the most before buying anything. But when I checked the products there I felt confused. Some brands looked professional but had very little information on the packaging. Some had good reviews online but mixed opinions from local gardeners. Some products were very cheap and that made me question the quality. I could not trust them. I could not decide confidently.

Then I visited another shop in the same area. Some potassium nitrate products looked cleaner and better packed. Some sellers explained how different brands work for vegetables flowers and fruit plants. Some still gave unclear advice about usage and quality. I remembered I once bought fertilizer from a local market because the seller promised fast plant growth but later my plants reacted badly after using it. That made me hesitate even more.

To check more variety and options while scrolling many online marketplaces including alibaba I found many potassium nitrate brands for gardening use. Some companies focused on high purity and balanced nutrition for plants. Some websites showed customer reviews with photos of garden results. Gardening forums and plant care groups also shared experiences from people using different fertilizer brands. Some products looked affordable but had limited reviews. Some looked expensive but seemed more trusted by experienced gardeners. There were many choices available online. This made me excited but also confused again.

Now I am thinking should I choose a well-known potassium nitrate brand with higher prices or try a cheaper option with decent online reviews before using it in my garden?