Dose Achieved from Chemical Added
Worked example: 10 lb into 5000 gal → 239.81 ppm — press Try an example to run it live, then adjust anything.
Enter your known values, leave one input blank, and solves for the missing one. Tap a variable’s symbol to see what it means, with a typical value. Try different units for next level excitement!
Dosing the loop →
UniversityProcess & Water Chemistry
Test your skills in the Exam Room: new numbers every attempt — free lessons for students, no sign-up, just pure learning.
share your results
Dose Achieved from Chemical Added explained
Run the feed equation backwards and you get the after-the-fact question every technician is asked: I dumped a pail in — where does that put me? Ten pounds of product into a 5000 gallon system is 10 lb spread through 5000 × 8.34 = 41,700 lb of water, which is 10/41,700 = 240 ppm. In metric the same idea is even simpler, since a cubic metre of water weighs about 1000 kg: one kilogram in ten cubic metres is 100 ppm.
The number that wrecks this calculation is never the arithmetic — it is the system volume. Nameplate volumes on closed loops are optimistic, and towers with deep sumps, remote basins or long buried runs routinely hold 30–50% more than the drawings say. If accuracy matters, measure it: add a known mass of an inert tracer such as lithium or a fluorescent dye, let it mix for a full turnover, test the residual, and solve this same equation for V. That trick is the basis of every tracer-controlled feed program on the market.
Dose Achieved from Chemical Added formula
- = Concentration achieved (%)
- = Mass of chemical added (kg)
- = System volume (L)
Missing one of these? Work it out first, then come back
- Concentration achieved — BOD Mass Loading, Glycol Dilution
- Mass of chemical added — Chemical Mass Consumed Over a Period, Pounds of Active Chemical in a Tank
- System volume — Closed Loop Slug Dose Volume, Holding Time Index