The most common cloud seeding method is called static cloud seeding. It involves spreading the chemical silver iodide into clouds,which is very effective because its structure is very similar to ice crystals. This process allows moisture to gather and condense on the silver iodide crystals. It's just like rolling a tennis ball (the crystal) through the snow. Some of the snow will attach itself to the tennis ball. A second type of cloud seeding is called hygroscopic cloud seeding.This process disperses salts into clouds through flares that are fired by large guns. The salts then grow as water attaches to them. When cloud seeding works, it can be an effective way to increase the natural supply.