Q.plants do not grow big
We have had gardens for a few years and the plants never grow very big or produce much food. we are on well water with sandy soil. I have noticed that after it rains the garden looks very pretty. So I am thinking something is wrong with the water. I would like to have an organic garden and any advice would be helpful.
I don't believe your well water is as big an issue as perhaps your sandy soil. Sandy soil drains well, but on the other hand will not hold moisture. If your plants perk up after a rain, it's most likely because they are receiving the moisture they are needing.
Amending your sandy soil with compost or good organic top soil would help your garden.
This may be the place to get started with your garden.
Here are a few links to help you get your garden growing.