+1 Drain Water Per Click Mutations Guide (All Multipliers)

Mutations are the fastest way to raise how much money your aquarium makes in +1 Drain Water Per Click. A mutated fish sells for more and earns more per cycle than the same fish without one, and the whole system runs on four tiers that stack no higher than a single mutation per fish.

Quick answer: Find a mutated fish anywhere on the map and grab it before it despawns. Gold gives 2x, Diamond 5x, Venom 10x, and Hole 20x on both sale value and earning rate. Venom and Hole are rare outside the Poison and Black Hole weather events, which each add +10% to their spawn chance for four minutes.

What a mutation actually does to a fish

A mutation applies one multiplier to two things at once. It raises the price you get when you sell the fish, and it raises the rate that fish earns while it sits in your aquarium. Nothing else about the fish changes, so a common fish with Hole can outperform a much rarer fish with no mutation at all.

You can spot a mutation without opening any menu. Each one recolors the fish and prints the mutation name above the fish’s normal name. Gold looks metallic and gold-tinted, Diamond is cyan, Venom is neon green, and Hole is very dark.

One hard rule shapes everything else. A fish can only carry a single mutation at a time, so there is no stacking a Gold fish into a Diamond fish for a combined multiplier.

All four mutations and their multipliers

Gold and Diamond do the heavy lifting early because they spawn on their own at a high rate. Venom and Hole are the payday tiers, and they are gated behind low base spawn odds unless the matching weather is running.

Mutation	Multiplier	Where it comes from
Gold	2x	High natural spawn chance in every area of the map.
Diamond	5x	High natural spawn chance in every area of the map.
Venom	10x	Low natural spawn chance. Poison weather adds +10% for 4 minutes.
Hole	20x	Low natural spawn chance. Black Hole weather adds +10% for 4 minutes.

Hole is the strongest mutation in the game right now at 20x, and Black Hole weather fires twice an hour, so it is the one worth building your session around.

How to get mutated fish

Mutated fish are not crafted, rolled, or bought. They spawn into the world already mutated, and you collect them on foot.

Move through the areas you have unlocked and watch the fish that appear around you. Mutated fish can show up in any area, so there is no single farming spot that locks you out.

Check the label above each fish. The mutation name sits above the regular fish name, and the recolor is usually visible before you are close enough to read the text.

Pick the fish up quickly. Spawned fish despawn after a while, so a Venom or Hole fish you walk past is gone rather than banked for later.

Place the fish in your aquarium so the multiplier starts feeding your earning rate, then keep the highest-value ones equipped instead of selling them off immediately.

Room screen with hotbar slot one selected and mutated fish stocked in the aquarium — The Room screen with the first hotbar slot selected, showing collected fish stocked in the aquarium. Image: Wrestling Elephant Studio

If you are starting fresh, the loop feeds itself. Draining pools opens new areas, new areas mean more spawn points to sweep, and a fatter aquarium bankrolls the pumps, auras, and pets you want. The experience runs on Roblox and is made by Wrestling Elephant Studio.

Poison and Black Hole weather events

Two weather events exist purely to make the top-tier mutations reachable. Poison weather raises the odds of Venom fish spawning by 10%, and Black Hole weather does the same for Hole fish. Both last four minutes.

Four minutes is short, so treat the event window as a sprint. Stop draining, stop shopping, and spend the whole timer moving between spawn points collecting anything that shows a mutation label.

Note: weather only changes what spawns. It does not retroactively mutate anything you already own, so a plain fish sitting in your aquarium or inventory stays plain no matter how many Black Hole events pass.

Why you are not getting Venom or Hole fish

Three things account for almost every dry streak, and none of them are fixed by moving to a different area.

You are farming outside the weather window. Venom and Hole both have a low base spawn chance, so hunting them during clear weather is mostly wasted time.
The fish despawned before you reached it. Spawns are temporary, and a high-tier mutation disappears on the same timer as a Gold one.
You are waiting for a mutation to be applied. There is no mechanic that adds a mutation to a fish you already caught. It either spawned with one or it did not.

You will know a run worked the moment the fish lands in your aquarium, because the mutation name stays attached to it and the payout climbs against an identical unmutated fish. Build the collection around Hole first, backfill with Diamond, and treat Gold as the floor you replace once your earning rate can carry the next round of upgrades.