What the aquarium does
The official Harpoon a Fish description tells players to put a caught fish in the aquarium and grow a new pet. Official badge metadata also includes a New Pet badge. Together, those sources confirm the basic input and outcome: a catch can be used through the aquarium as part of pet progression.
They do not provide a complete current slot table, growth timer, income formula, feeding rule, offline behavior, or replacement policy. Current community guides discuss several of those details, but the aquarium interface in your server should settle every exact value before you commit a valuable catch.
Place a caught fish
The aquarium accepts a caught fish as part of its intended loop. Verify the exact selected fish before confirming.
Grow a new pet
Pet growth is stated in the game description and supported by the New Pet badge. The current timer or condition must be read live.
Extra aquarium benefits
Current guides describe slots, growth behavior, and earnings. Treat the visible live values as authoritative because exact rules may change.
Before placing a fish
Secure the catch and move through the decision calmly. The official description includes stealing other players’ fish, so do not leave a useful catch exposed while studying several menus. Open the aquarium only after the catch has registered in the Index or inventory state you expect.
Read the entire placement screen. Confirm the selected fish name, the destination slot, any visible growth condition, and any replacement warning. If the interface offers a preview, record it. If a field is absent, leave it unknown rather than borrowing a number from an old video.
Use a replaceable fish for the first test. A common catch lets you learn the system without risking your only new Index entry, a monster, or a species record candidate.
Placement checklist
- Catch a fish you can obtain again.
- Confirm its exact name and Index registration.
- Open the aquarium and identify the selected slot.
- Verify that the selected fish is the one you intend to use.
- Read any timer, growth, cost, or replacement text shown by the current game.
- Record the before state, including fish and pet slots.
- Confirm once, then record what changed.
- Reopen the aquarium after a normal play interval and after rejoining to test persistence.
This procedure answers what happened in your account without assuming that all slots or catches behave identically.
Choose the right fish
A catch can serve several goals. It may add a new Index entry, support weight and depth progression, qualify for a record attempt, become an evolution input, or go into the aquarium. Compare those uses before committing it.
Good first test
An ordinary fish with a confirmed name that you can catch again. Its live placement preview is clear, and no important replacement warning appears.
Pause before using
A new Index entry, unusually measured catch, or fish with an unclear selection or result. Keep it while you inspect the alternatives.
High-caution catch
An officially named sea monster or record candidate. Do not use it merely because a community chart claims a benefit that the live screen does not show.
The right choice may change with your goal. A player filling the Index values a first copy differently from a player testing pet growth. State the goal before opening the confirmation dialog.
Track pet growth
After placement, record the pet or aquarium state the game shows. Look for a name, timer, progress bar, condition, or claim control. Note the UTC date and whether you remain online. Current community material reports specific growth and online behavior, but those precise claims need live confirmation before being treated as rules.
Check at sensible intervals rather than reopening the panel continuously. When the state changes, capture the before-and-after display. If the pet becomes claimable, verify the selected result before pressing a final button. Record whether the source fish remains, changes, or disappears.
The official New Pet badge may help confirm that the outcome registered, but a badge alone does not explain the timer or slot behavior.
Verify slots, earnings, and offline behavior
Community guides describe aquarium slots and ongoing benefits, sometimes including cash-related behavior. These are useful leads, not permanent values. To verify a slot, count only the active positions shown by your account and note whether locked positions display requirements. To verify earnings, record the balance before and after a controlled interval with no other income action.
To test offline behavior, record the aquarium and balance state, leave normally, and return after a known interval. Compare the result once. Do not claim a rate from a single session if another mechanic could have supplied the reward. Repeat under comparable conditions.
If the interface says that staying online changes growth, preserve the exact wording and date. If it does not, keep the field unknown rather than repeating a community percentage.
Claim and equip a pet
When the game indicates that a pet is ready, read the claim screen. Verify the pet name and any displayed effect. After claiming, check the pet inventory or equip interface. Record whether claiming frees the aquarium slot and whether another action is required.
Do not assume every pet supplies the same effect or that visual rarity equals power. Use the actual in-game label. If an effect is expressed as a number, note the conditions under which it applies. Compare account state before and after equipping to confirm the result.
If the New Pet badge does not appear immediately, reopen the relevant panels and allow normal Roblox badge delivery time. A delayed badge does not necessarily mean the pet failed to register.
Fix common aquarium problems
The fish is missing from the selection list
Confirm that the catch finished, registered, and is stored where the aquarium reads it. Check whether it is already assigned to evolution or another slot. Read any eligibility message rather than guessing a rarity requirement.
Placement is blocked
Inspect the destination slot and every displayed requirement. A slot may be occupied or locked, or another condition may be missing. If the interface appears stale, rejoin a fresh official server and test with an ordinary catch.
Progress appears frozen
Record the visible state and wait a defined interval. Reopen the panel and rejoin once. Compare online and rejoined states without changing several other variables. If the game presents a required action, follow the current prompt.
A fish or pet would be replaced
Stop at the warning. Identify both the existing and incoming item. Confirm only when the tradeoff is understood. Keeping the catch is better than accepting an unclear replacement.
Maintain an aquarium log
For each placement, record the fish name, visible attributes, slot, placement time, displayed condition, observed completion time, pet result, visible effect, and check date. Add a verification state: official feature, live observation, community report, or needs testing.
Do not manufacture missing fields. A short accurate log can be compared after an update, while a complete-looking guessed chart cannot.
Sources and check date
- Official Harpoon a Fish Roblox experience — placing a caught fish and growing a new pet.
- Official Roblox badge metadata — New Pet outcome.
- Current community guides checked October 17, 2026 — slot, growth, and benefit claims used only as questions to verify in the live interface.
This aquarium guide was checked on October 17, 2026. Exact slots, timers, rates, eligibility, replacement behavior, income, offline progress, and pet effects remain live-game values unless the interface states them.