What aquarium upgrades are confirmed?
The confirmed paid boosts relevant to Harpoon a Fish aquarium progress are -50% Grow Time [PERMANENT] and 2x Money [PERMANENT]. The first advertises shorter fish growth time; the second advertises more cash from your animals. These are gamepasses, and neither listing establishes a route for buying more aquarium slots or upgrading the tank itself.
FirstTry's game description confirms that caught fish can be placed in an aquarium and grown as pets. However, the official information checked on October 17, 2026 does not publish aquarium slot costs, tank upgrade tiers, base growth timers, or per-fish income rates. Those gaps matter when deciding whether your problem is waiting for growth, earning cash, or needing capacity.
Fish growth and cash boosts compared
The official Harpoon a Fish gamepass listing provides the following descriptions and sale information. The prices below are the October 17 API snapshot; the live Roblox purchase screen is the place to confirm a price before paying.
| Pass | Advertised effect | Listed price | Availability |
|---|---|---|---|
| -50% Grow Time [PERMANENT] | Halves fish growth time. | 349 Robux | For sale |
| 2x Money [PERMANENT] | Doubles cash from your animals. | 249 Robux | For sale |
| VIP | Includes 20% less growth time and 1.5x cash, plus five bag spaces and a nametag. | No current price | Not for sale |
For the growth pass, halving a timer means taking 50% of its original duration. As a mathematical example only, a 20-minute timer would become 10 minutes; 20 minutes is not a confirmed timer for any fish in this game.
The cash pass describes the source of its bonus as animals. It does not establish that every currency reward is doubled, nor does it publish an earnings-per-hour figure. Without baseline income data, there is no supported calculation for how quickly a purchase would pay off.
Check capacity separately from faster growth
If your goal is simply to raise a caught fish, begin with the aquarium placement described by the developer and follow the game's current prompts. If you are looking for an upgrade, first identify what the visible option actually changes:
- Growth time: compare the stated timer effect. Faster growth does not, by itself, establish more slots.
- Animal cash: compare the cash description with the earnings displayed in your session, if available. Do not substitute an income figure from another fishing game.
- Aquarium capacity: check for an explicit aquarium-slot benefit and its displayed cost. The verified pass descriptions do not provide that information.
- Bag capacity: +10 Bag promises 10 more bag spaces and says it stacks with VIP. That wording does not promise 10 more aquarium spaces.
VIP's listed growth and cash benefits remain visible even though it is not currently for sale. The official response also does not explain how those bonuses combine with the separate growth or money passes. A combined timer reduction or cash multiplier would therefore need further confirmation.
FAQ
How much does it cost to upgrade the aquarium?
The checked official information does not give tank upgrade or slot prices. It lists the separate growth-time pass at 349 Robux and the animal-cash pass at 249 Robux; those prices should not be presented as aquarium expansion costs.
Does the growth pass add more fish slots?
Its description says fish growth time is cut in half. It does not advertise additional slots or a larger aquarium.
Can I buy VIP for its aquarium-related bonuses?
VIP was marked not for sale in the October 17 response, with no current price. That does not mean it is free, and the response does not announce when it might return.
Which fish should I keep for the highest aquarium income?
The available official descriptions do not provide a species-by-species income table or a verified best-fish ranking. Use the values actually displayed in your game, where available, rather than importing a ranking from Fisch or another Roblox experience.