This Soil Moisture Meter 3 in 1 was designed for houseplants for plant lovers. This Soil Meter is a widely applications for indoor outdoor plants [Farm, Garden, Lawn, Balconies, Greenhouses, Office, etc.] Lets you know when to water. Helps you determine if plant is getting adequate light. Helps you control pH level in soil. Multi-function 3-in-1 Soil Meter Features: 1. Plug and Play 2. No Batteries Required 3. Fast Test 4. Portable Design 5. Application for Both Indoor Outdoor Plants Important Tips: 1. Never try to test water or put it into liquid. (No test result when sensors in water/liquid) 2. Don't insert into solid or very hard soil. 3. Water plants before test if the soil is too dry. 4. Don't leave the Soil pH Sunlight Moisture Meter in the soil for long periods of time. pH ADJUSTMENT 1. Soil Acid Adjustment. Generally uses lime, to achieve the purpose of neutralizing active acid, latent acid and improving soil structure. Can also use calcium-containing shell ash, purple shale powder, fly ash and plant ash to instead. 2. Artificial Acidification the Neutral and Calcareous Soil. Sulfur powder (50g/m2) or ferrous sulfate (150g/m2) can reduce 0. 5-1 pH unit. Can also use Alum fertilizer, water to instead. 3. Alkaline Soil Adjustment. Can use gypsum, phosphogypsum, ferrous sulfate, sulfur powder, and acid weathered coal.