pHusion Calcitic Limestone is a calcitic pelletized limestone that is reacted with an organic acid. This unique organic acid is a combination of Calcium Lignosulfonate and Lignosulfonic Acid. University tests show that 500 lbs. of limestone treated with organic acid gives equal or better results than one ton of traditional pelletized limestone per acre. pHusion Calcitic Limestone increases the soil pH as much as 4 times faster than conventional limestone products at similar application rates.