#fertilizer

Planted-aquarium and aquascaping maths as an API, computed locally and deterministically — the dosing and water numbers a high-tech planted tank runs on, not the rolls of a dice. The co2 endpoint gives the dissolved CO2 concentration from pH and carbonate hardness using the classic relationship CO2 (ppm) ≈ 3 × KH (dKH) × 10^(7 − pH), and flags it against the 15–30 ppm window plants want — at pH 6.6 and KH 4 you are at about 30 ppm, the top of the safe zone, while pH 7.0 and KH 3 is a carbon-limited 9 ppm. The fertilizer endpoint turns a dry-salt dose into the nutrient ppm it adds, the heart of Estimative Index dosing: ppm = grams × the nutrient mass fraction × 1000 ÷ tank litres, so 1 g of KNO3 in 100 litres adds 6.1 ppm nitrate and 3.9 ppm potassium, and it knows KNO3, KH2PO4, K2SO4, MgSO4 (Epsom) and Ca(NO3)2. The substrate endpoint sizes the substrate from the footprint and target depth — a 60 × 30 cm tank at 6 cm deep needs 10.8 litres, two 9-litre aquasoil bags. Everything is computed locally and deterministically, so it is instant and private. Ideal for aquascaping and planted-tank apps, fertiliser-dosing calculators, CO2-rig tools, and aquarium-shop and hobby sites. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 compute endpoints. For a tank water volume or fish stocking use an aquarium API; for pool chemistry use a pool API.

api.oanor.com/aquascape-api

Fertilizer maths as an API, computed locally and deterministically. The rate endpoint works out how much fertilizer product to apply to hit a target nitrogen rate over an area: from the N-P-K analysis (such as 10-10-10 or 20-5-10), a target pounds of nitrogen per 1000 ft² (or per 100 m²) and the area, it returns the product weight and the pounds of nitrogen, phosphate and potash applied. The nutrients endpoint reports the pounds of nitrogen, P₂O₅ and K₂O — and the elemental phosphorus and potassium — in a bag of a given weight and analysis. The coverage endpoint works out how much area a bag covers at a target nitrogen rate. N-P-K are percent by weight; phosphorus is reported as P₂O₅ and potassium as K₂O following the label convention, with the elemental amounts alongside (P₂O₅ × 0.4364, K₂O × 0.8301). Everything is computed locally and deterministically, so it is instant and private. Ideal for lawn-care and gardening apps, agriculture and turf tools, and landscaping and quoting software. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is fertilizer rate maths; for mulch, gravel and topsoil quantities use a landscaping API.

api.oanor.com/fertilizer-api