I use DE and it is great. It adds silica and calcium, plus it is PH Neutral.
Here is the soil reciepe I use after two years of adjusting to meet my grow style and environment.
Soil Recipe
2 CU F Soil Base
1 Cup Soybean Meal 7-2-1 Nitrogen and Potassium Lasts in soil for 1-2 years.
1 Cup Neem Meal 6-1-2 stimulates growth of plants and microbes in compost and soil protects against soil and root pets
1 Cup Kelp Meal 1-0-4 potassium, magnesium, calcium, and nitrogen full of trace Minerals, Carbohydrates and Amino Acids
1 cup Alfalfa Meal 3-.5-3 phosphorus potassium calcium, magnesium, sulfur, Manganese, iron, copper, boron, and zinc
1/2 cup Langbeinite 0-0-22 potassium, magnesium, and sulfur neutral PH
4 cups rock dust trace minerals and micronutrients feeds microbes
2 cups oyster shell flour Its calcium helps balance soil pH levels, improves nitrate uptake, aids enzyme formation and strengthens plant cell walls
5 cups worm castings Nitrogen, feeds microbes, adds organic matter, enhance seed germination, plant growth, flowering and fruit production.
2+ cups Diatomaceous Earth Adds Silica PH Neutral Calcium great for plant cell growth,
1/2 cup BSF Frass blend of N-P-K and minerals chitin good for plant health and disease resistance, feeds microbes
If you want to see the results I have posted a ton of images of my forever grow.