Grow substrate dryback log calculator

Calculate observed retained water per reading and interval water-mass dryback with your own figures.

Your numbers

Use the units shown. Results update as you change valid inputs.

Use observed retained water per reading and interval water-mass dryback to compare changes to your inputs. The method and limits below explain the scope.

Examples

Examples

Try the starting example

Container [time hours,total mass g]
[[0,1300],[12,1200],[24,1100]]
Dry container-plus-substrate baseline (g)
800
Water density (g/mL)
1
Observed retained water per reading (mL)
[[0,500],[12,400],[24,300]]
Interval water-mass dryback
[[0,12,100,8.33333333333,0.2],[12,24,100,8.33333333333,0.25]]

Try another scenario

Container [time hours,total mass g]
[[0,1300],[12,1200],[24,1100]]
Dry container-plus-substrate baseline (g)
900
Water density (g/mL)
1
Observed retained water per reading (mL)
[[0,400],[12,300],[24,200]]
Interval water-mass dryback
[[0,12,100,8.33333333333,0.25],[12,24,100,8.33333333333,0.333333333333]]
Calculation method

Calculation method

Observed retained water per reading (mL)

(Mass−dry baseline)/water density.

Interval water-mass dryback

[start,end,mL loss,mL/hour,loss fraction of preceding water]; gains remain signed.

Symbols and units
a
Container [time hours,total mass g]
b
Dry container-plus-substrate baseline (g)
c
Water density (g/mL)

Use the units shown. A list keeps the order in which you enter its values. The symbol ^ means “raised to the power of”.

Assumptions & limits

Assumptions & limits

  • Timed container weights, dry baseline. Returns Water-content change between readings. All coefficients and observations are user supplied; results describe only the stated mathematical model. Quantities are deterministic calculations from supplied observations and assumptions; no external data is fetched. Supported limits: Finite inputs only; numeric fields bounded as labelled. Lists and JSON records are limited to 256 entries unless a stricter tool bound is stated. No automatic design approval, legal conclusion, treatment recommendation or safety certification. Dry container-plus-substrate baseline (g): minimum 1e-12, maximum 1000000000000.0. Water density (g/mL): minimum 1e-12, maximum 1000000000000.0.
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