You have been using very light media with no soil in it.  I recommend that you add soil (not much clay) to your mixture.  If you have access to good soil, it will add microbes that will aid in nutrient uptake for your plants. You can also add some sand, but this will increase porosity and not increase the nutrient value of the soil.  Look for sandy loam.  (This should be available in Southern Wake as the soil changes to coastal plain there and has much more sand in it.)

I suggest you read chapters 1 and 16 in the Extension Gardener Handbook, https://content.ces.ncsu.edu/extension-gardener-handbook, for information about soil for your raised garden beds.

You have been using very light media with no soil in it. I recommend that you add soil (not much clay) to your mixture. If you have access to good soil, it will add microbes that will aid in nutrient uptake for your plants. You can also add some sand, but this will increase porosity and not increase the nutrient value of the soil. Look for sandy loam. (This should be available in Southern Wake as the soil changes to coastal plain there and has much more sand in it.)

I suggest you read chapters 1 and 16 in the Extension Gardener Handbook, https://content.ces.ncsu.edu/extension-gardener-handbook, for information about soil for your raised garden beds.