Week 5 Tutorial: Species, months and the approval you need

Week 5 tutorial — size the fish and bed pair from the feed-rate ratio, then find out what your client's jurisdiction actually requires before keeping anything

25 March 2027

Time

90 minutes in the room, plus about 30 to tidy the output

Graded

Checkpoint 4 of 10, 2 % — a good-faith attempt at the output below

Due

5 pm, 26 March 2027

What this tutorial is for#

Aquaponics is sized from the feed — not from the fish and not from the plants. That makes the arithmetic short. The rest of the session is the part the model cannot see: what you are legally allowed to keep.

Story stage. Scoping. Quiz 2 runs at the start, on weeks 4 and 5.

Open these first#

• Your workbook, week 4’s feed balance — it caps how much of the fish is yours.
• Week 5’s lecture for the FAO feed-rate ratio and the stocking limit.
• Your home’s place and jurisdiction on its dossier.

If you missed week 4#

Use the labelled practice figure and redo it later: PRACTICE — assume 20 % of fish feed is grown on site and 80 % imported. A round number for teaching, not a result for any of the five homes.

The words this week uses#

• Feed-rate ratio — grams of fish feed per square metre of grow bed per day. FAO Technical Paper 589 gives the range a small system is sized from.
• Stocking density — kilograms of fish per 1,000 L of tank. The FAO limit for a small system is 20 kg per 1,000 L.
• FCR — feed conversion ratio, feed mass per unit of fish mass gained.
• Fillet yield — the edible fraction of a whole fish.
• Counted protein — the fish protein grown on your own feed. Fish grown on bought feed are bought fish.

Do this#

1. Quiz 2 (20 minutes). On paper, on weeks 4 and 5.

2. Size from the feed (25 minutes). Bed area, feed rate, stocking density, FCR, fillet yield, in that order. Then check your stocking against 20 kg per 1,000 L before you go any further; a surprising number of first attempts exceed it by a factor of two.

3. Write down the operating conditions (10 minutes). Temperature band, pH, alkalinity — the conditions a running system has to hold, with units. Put them on sheet 3 of your workbook as candidate measurement rows. They are what a monitoring programme would watch, and in week 9 you will read a troubleshooting log of a system that lost one of them.

4. Then the legal work, which is the real activity (30 minutes). Find the instrument. Not a forum post, not a supplier’s page — the Act, the regulation or the government page that carries the requirement. Canberra students will find that the model’s own preferred species is the one they cannot keep without a licence. Queensland, South Australian and Northern Territory students will find their aquaculture definitions turn on sale, which is why their answer is shorter.

Write down what you found and where. You will need it in Assignment 2’s compliance section.

5. Net the protein off (5 minutes). Counted fish protein is the small number, after week 4’s import share. Carry that one, not the gross.

The output#

A sized fish and bed pair, the species named with its approval pathway and the instrument cited, and the counted protein figure net of imported feed.

Check your own before you submit#

1. Is the bed area derived from the feed rate rather than chosen?
2. Is stocking density under 20 kg per 1,000 L?
3. Does your species row name its temperature band and where that band came from?
4. Have you cited an actual instrument — an Act, a regulation or a government page — rather than a supplier?
5. Is the protein you carried forward net of imported feed?
6. Are the operating conditions on sheet 3, with units?

Where it goes next#

Week 6 assembles everything you have learned you do not know into Assignment 1. Your fish operating conditions are three of its rows.

Back to week 5 overview