Source: https://guthlabs.ai/docs/instruments/aquarium-volume-stocking-calculator/implementation/

instrument implementation / implementation-contract

# Aquarium Volume & Stocking Calculator implementation

A source-bound implementation contract for Aquarium Volume & Stocking Calculator; deployment and executable qualification remain separate.

Status: **VERIFIED_CLEAN**Lifecycle: **implementation-contract**

## Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

**Record owner**: Guth Instruments

**Lifecycle**: verified-clean

**Evidence ID**: t4-280

**Effect**: Computation or source lookup only

## Input and validation requirements

The specification exposes multiple failure hazards: zero dimensions can yield a numerically valid but physically impossible zero-gallon tank, enormous dimensions overflow to Infinity, the adjusted stocking branch lacks enough formula detail to compute an output, and negative dimensions can produce a physically meaningless negative volume unless an explicit sign convention and validation rule are implemented.

## Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

## Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

````
{
  "inputs": {
    "method": "one_inch_per_gallon",
    "length_in": 48,
    "width_in": 13,
    "height_in": 20,
    "fish_adult_lengths_in": [
      6,
      4,
      4,
      2
    ]
  },
  "expected_outputs": {
    "volume_gal": 54.03,
    "maximum_aggregate_adult_fish_length_in": 54.03,
    "current_aggregate_adult_fish_length_in": 16,
    "remaining_rule_of_thumb_capacity_in": 38.03,
    "status": "within heuristic"
  },
  "working": "1. Tank volume = (48 × 13 × 20) / 231 = 12,480 / 231 = 54.025974... gal, displayed as 54.03 gal. 2. Maximum aggregate adult length under the heuristic = 54.025974... × 1 in/gal = 54.025974... in, displayed as 54.03 in. 3. Current aggregate length = 6 + 4 + 4 + 2 = 16 in. 4. Remaining heuristic capacity = 54.025974... − 16 = 38.025974... in, displayed as 38.03 in."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/aquarium-volume-stocking-calculator/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/aquarium-volume-stocking-calculator/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/aquarium-volume-stocking-calculator/qualification/>)

## Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

- `VERIFIED_LEDGER.json`

- `evidence-tranche4/tranche4-results.json`