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THE FEUTEX TOOLKIT

Aquarium Evaporation Top-Off Reserve

Estimate reserve duration from observed daily evaporation and usable reservoir volume.

Aquariums workspace● Runs in your browser
01 Your input
02 Your result
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FormulaDaily evaporation = (start_water-end_water)/observation_days; Reserve days = (reservoir-unusable)/((start_water-end_water)/observation_days)

Worked example

Inputs

Reservoir
30 L
Unusable
3 L
Start water
100 L
End water
94 L
Observation days
3 days

Expected results

Daily evaporation
2 L/day
Reserve days
13.5 days

Load the example in the workspace to reproduce these results. Display rounding does not change the underlying calculation.

How to use this tool

  1. Enter the measured quantities and your own planning assumptions.
  2. Review all calculated outputs and the stated limitations.

Try this example

{
  "reservoir": 30,
  "unusable": 3,
  "start_water": 100,
  "end_water": 94,
  "observation_days": 3
}

Accuracy and scope

Assumes observed loss is evaporation, not leakage, and remains constant. No water chemistry, salinity correction or animal-care recommendation.

Is my data uploaded?

This tool runs locally in your browser. Input and output are not sent to a processing server. Copy or download your result before leaving the page.