Units:
← All Calculators

General Utility Calculators

Chemical feed pump sizing and pH/acid-base dosing — free, client-side, no sign-up required.

CALCULATOR 1 OF 2

Chemical Feed Pump Sizing

Calculate metering pump output to achieve a target chemical dose in your process stream. Supports continuous feed and batch/slug dosing modes.

Process & Chemical
Enter a positive flow rate.
Enter a positive dose value.
Enter concentration 0–100%.
Enter SG between 0.5 and 2.5.
 
Feed Rate
—GPH
Feed Rate
—mL/min
lb/day Active
—lb/day
lb/day Product
—lb/day
Full Output Summary
Parameter US / Imperial Metric (SI)
Feed Rate——
Feed Rate——
Active ingredient——
Product (as-is)——
Annual consumption——

Continuous Feed Formulas

C_active (mg/mL) = (C_prod_% / 100) × SG × 1000

Q_process (L/min) = GPM × 3.785

Feed rate (mL/min) = Q_process × dose_mg_L / C_active

Feed rate (GPH) = mL/min × 0.01585

Feed rate (oz/day) = mL/min × 1440 / 29.574

Feed rate (lb/day product) = mL/min × SG × 1440 / 453.6

Feed rate (lb/day active) = lb/day_product × (C_prod_% / 100)

Annual consumption (gal/yr) = GPH × 8760

Batch / Slug Formula

Vol_product (gal) = system_vol × (C_target − C_current) / (C_prod_frac × 1,000,000)

  • C_prod_frac = C_prod_% / 100 (product active fraction)
  • Concentrations in ppm (mg/L), volumes in gallons
  • SG correction: actual volume = vol_product; mass = vol × SG × 8.34 lb/gal
CALCULATOR 2 OF 2

pH / Acid–Base Dosing Estimator

Estimate acid or base dose required to shift pH from a current value to a target value, accounting for alkalinity (carbonate buffering) and temperature. Based on the full carbonate equilibrium system.

Water Chemistry
Enter pH between 2 and 12.
Enter pH between 2 and 12. Must differ from current.
Enter a valid temperature.
Enter alkalinity ≥ 0.
Enter a positive flow rate.
Chemical Selection
Dose Required
—meq/L
As 100% Chemical
—mg/L
Feed Rate
—GPH
Detailed Results
Parameter Value Units
Chemical dose required—meq/L
Dose as 100% pure chemical—mg/L
Product feed rate (mL/min)—mL/min
Product feed rate—GPH
Alkalinity remaining at target pH—mg/L CaCO₃
CO₂ at target pH—mg/L

Carbonate Equilibrium Constants (temperature-corrected)

T_K = (°F − 32) / 1.8 + 273.15

pK₁(T) = 6.352 + 485.0/T_K − 0.00884×T_°C

pK₂(T) = 10.329 + 863.0/T_K − 0.01273×T_°C

pKw(T) = 4787.3/T_K + 7.1321×log₁₀(T_K) + 0.010365×T_K − 22.801

Alkalinity → Carbonate Species

Alk_meq = Alk_mgL / 50.04

CT = Alk_meq / (α₁ + 2α₂ + [OH⁻]/[H⁺])

where α₁, α₂ are carbonate fraction terms at initial pH.

Acid Dose (mineral acid)

dose_meq = Alk_initial − Alk_final(pH_target)

Alk_final calculated from CT held constant across target pH.

Product Feed Rate

C_product (g/L) = % × SG × 10

Feed (mL/min) = Q(L/min) × dose_mgL_100pct / (C_product_gL × 1000)

  • H₂SO₄: 1 meq = 49.04 mg 100% H₂SO₄ (diprotic)
  • HCl: 1 meq = 36.46 mg 100% HCl (monoprotic)
  • NaOH: 1 meq = 40.00 mg 100% NaOH
  • Na₂CO₃: 1 meq = 53.00 mg 100% Na₂CO₃ (diprotic)
  • Ca(OH)₂: 1 meq = 37.05 mg 100% Ca(OH)₂ (diprotic)
  • CO₂: dose as mg/L CO₂; gas rate in lb/day via Q(MGD)×dose×8.34