Frequently Asked Questions

Yes! Our core suite of agronomic calculators—including the Lime Requirement, pH Down, and Fertilizer Blend tools—are 100% free for home gardeners, landscapers, and commercial farmers. We believe precision soil management should be accessible to everyone.

SoilTune is built for anyone who manages soil. This includes backyard gardeners growing acid-loving plants (like blueberries), lawn care professionals managing turfgrass, and commercial agronomists blending custom N-P-K fertilizers for large-acreage row crops.

No account is required to use the calculators. You can input your soil data and get instant recommendations as a guest. However, creating a free account allows you to save multiple "Soil Profiles" (e.g., Front Yard, Blueberry Patch, North Field) for quick reference later.

Home test kits (like Rapitest or LaMotte) are great for getting a baseline active pH. However, they cannot measure Buffer pH or CEC (Cation Exchange Capacity). Because our advanced algorithms rely on Buffer pH to calculate exact lime requirements for clay or loam soils, we highly recommend sending a sample to a professional lab or local university extension for the most accurate results.

Active pH measures the hydrogen ions currently floating in the soil water. Buffer pH (or reserve acidity) measures the hidden hydrogen and aluminum ions attached to clay and organic matter particles. Think of active pH as the "tip of the iceberg." Two soils can have the exact same active pH, but if one is clay (high buffer) and one is sand (low buffer), the clay will require vastly more lime to change its pH.

For general lawn and garden maintenance, testing every 2 to 3 years is sufficient. If you are actively trying to correct a severe pH imbalance or managing high-value commercial crops, you should test annually, ideally at the same time of year (preferably early spring or late fall) to maintain consistent baselines.

ECCE stands for Effective Calcium Carbonate Equivalent (sometimes called ENV - Effective Neutralizing Value). It is a percentage that accounts for both the chemical purity of the lime and how finely it is ground (particle size). Our calculator uses this number to adjust your application rate so you aren't under-applying a lower-quality product.

Safety first! Applying too much elemental sulfur or aluminum sulfate at once drastically spikes soil salinity and acidity, which will cause severe "root burn" and can kill your plants. Our calculator enforces strict agronomic safety limits (e.g., max 20 lbs of sulfur per 1,000 sq ft). If your target requires more, the tool automatically calculates a safe, multi-month schedule.

Soil amendments are not instant. Elemental sulfur relies on soil bacteria to convert it into sulfuric acid, which takes 4 to 8 weeks (and requires warm, moist soil). Agricultural lime is a slow-moving rock dust; it can take 6 to 12 months to fully react and move through the soil profile, especially if it is only top-dressed and not tilled in.

Our algorithm uses sequential algebraic solving. It fulfills your Potassium (K) requirement first, then your Phosphorus (P) requirement. If your chosen P source (like MAP 11-52-0) also contains Nitrogen, the calculator calculates exactly how much "free" N was added, subtracts it from your total N goal, and only adds enough pure N source (like Urea) to make up the exact difference. This prevents toxic over-application.

Fertilizer N-P-K ratios are legally required to be measured by weight, not volume. A gallon of water weighs 8.34 lbs, but a gallon of heavy liquid fertilizer (like 10-34-0) weighs about 11.5 lbs. The calculator uses the specific liquid density to convert your gallon inputs into pounds so the nutrient math remains perfectly accurate.

If you are using a mechanical broadcast spreader, it is often calibrated to spread a specific total weight per acre (e.g., 400 lbs/acre) for even coverage. If your active N-P-K nutrients only weigh 150 lbs, the calculator will tell you to add 250 lbs of inert "filler" (like pelletized gypsum, sand, or limestone) to bulk up the batch so your spreader operates correctly.

Absolutely not. We do not sell your data to agro-chemical companies, data brokers, or third parties. If you use the calculators as a guest, the math happens locally in your browser. If you save a Soil Profile to your account, the data is encrypted and stored securely solely for your personal reference.

Yes. You have full control over your data. You can delete individual Soil Profiles at any time, or navigate to your Account Settings to permanently delete your account. Upon deletion, all your personal soil data is immediately purged from our active servers.