TNB PH UP and DOWN 1lb/454g set TNB Naturals Up and Down are composed of all natural ingredients with the addition of no harmful chemicals. This innovative way to raise and lower the pH levels of your hydroponic or liquid fertilizer is both simple and cost effective. Simply add a small amount to your water, mix thoroughly and check your pH levels. The pH (potential hydrogen) of a nutrient solution is a very important aspect of plant growth and proper management is essential for healthy plants and lush gardens. TNB Naturals Up and Down are composed of all natural ingredients with the addition of no harmful chemicals. This innovative way to raise and lower the pH levels of your hydroponic or liquid fertilizer is both simple and cost effective. Simply add a small amount to your water, mix thoroughly and check your pH levels. The pH (potential hydrogen) of a nutrient solution is a very important aspect of plant growth and proper management is essential for healthy plants and lush gardens. TNB Naturals Up and Down provides growers with a user friendly and safe way to maintain appropriate pH levels for optimal plant growth.