Quick answer: Keep one adult pearlscale in a 20-gallon long tank with sinking goldfish food. Add 10 gallons for each extra fancy goldfish. Skip bowls, tropical fish, and floating pellets.
One adult pearlscale goldfish needs a tank of at least 20 gallons.
This page is a research-desk comparison of published tank dimensions and goldfish-food labels. We did not keep pearlscales in house, run feeding trials, or open fish.
How we chose what this page covers
A tank or food enters this page only if it passes the Pearlscale 20-and-Sink Rule.
That rule is our own cut, and it is easy to check on a maker page.
- Tank: the maker must publish a filled weight for a rectangle of 20 gallons or more.
- Food: the maker page must list a sinking pellet or granule, and it must name fancy goldfish or pearlscales.
- Roommate: the fish must be another fancy goldfish of like size, or it stays off this page.
Our research team compared Aqueon’s published tank chart with four current goldfish foods. We left out bowls, Mini Bows, flake-only diets, and tropical community fish.
What a pearlscale goldfish is
A pearlscale is a round fancy goldfish, not a small tropical pet.
Aqueon’s Goldfish Care Guide names pearlscales with orandas, ryukins, moors, and ranchus. It says all of those types are one species, Carassius auratus. The same page says people first kept goldfish in China over 1,000 years ago.
That long history does not make a bowl safe. Aqueon says goldfish grow large and make a lot of waste.
Pearlscales have raised, bumpy scales and a deep, round body. They are weak swimmers and lose food contests to fast single-tail goldfish.
Aqueon says goldfish can live over 20 years when cared for well. Plan the tank for an adult carp, not for the two-inch fish in the bag.
Tank size: start at 20 gallons
Start one adult pearlscale at 20 gallons, even though Aqueon’s fancy floor is lower.
Aqueon’s care guide gives each adult fancy goldfish at least 10 gallons. It gives each adult common, comet, or shubunkin at least 20 gallons. It also says never use a bowl, a small tank, or any box with no filter.
Our desk still starts at 20 gallons for the first pearlscale, and Aqueon’s own dimension chart is why.
Aqueon’s 20 Long is 30¼ by 12½ by 12¾ inches. Empty it weighs 25 pounds, and filled Aqueon lists 225 pounds.
Aqueon’s 20 High holds the same 20 gallons and the same 225 filled pounds. It is only 24¼ inches long. That is 6 inches less swimming length than the 20 Long.
Pearlscales need a long floor more than a tall box. Pick the 20 Long over the 20 High when both are on the shelf.
Use this gallon math, then match it to Aqueon’s published rectangles:
- One adult pearlscale: 20 gallons.
- Each extra fancy goldfish: add 10 gallons.
- Two adults: 30 gallons.
- Three adults: 40 gallons.
Aqueon’s 29-gallon tank is 30¼ by 12½ by 18¾ inches. It lists 40 pounds empty and 330 pounds full. It misses our 30-gallon pair floor by 1 gallon.
Aqueon’s 40 Breeder is 36 3/16 by 18 1/4 by 16 15/16 inches. It lists 58 pounds empty and 458 pounds full, so it clears a two-fish or three-fish plan.
Aqueon’s Mini Bow 5 is 14¾ by 9½ by 15⅛ inches and lists 55 pounds full. It fails the 20-gallon rectangle rule. Do not use it.
Put the tank on a stand built for the filled weight. Aqueon says filled weights can rise once gravel and décor go in.
Skip sharp rocks and lava rock. Aqueon says those edges tear fins and eye sacs on other fancy types. Pearlscale scales chip the same way.
Aqueon names Cryptocoryne, Java fern, and Anubias as plants goldfish may leave alone. It also says they may still uproot them. Soft sand or smooth gravel is safer than crushed glass.
Water, heat, and weekly changes
Hold fancy-goldfish heat and a fixed water-change clock, or waste will climb.
Aqueon’s care guide sets fancy goldfish at 68°F to 74°F. It sets comets and shubunkins at 60°F to 70°F. Pearlscales sit in the fancy band.
The same page sets an ideal pH of 7.0 to 8.4 and warns that fast swings in heat or chemistry can kill goldfish.
Aqueon’s water clock is a number, not a guess:
- Change 10% of the water each week, or
- Change 25% every 2 weeks.
- Treat new tap water before it goes in.
Aqueon also lists 1 tablespoon of aquarium or sea salt per 5 gallons as an optional health aid. That dose is not a license to skip water changes.
Aqueon says the filter should be slightly oversized. Add extra air if you keep the tank on the warm end of 68°F to 74°F.
Hikari’s page for Saki-Hikari Fancy Goldfish gives a second heat gate for food. It says to cut the meal when water stays below 50°F or above 86°F.
Those marks sit outside Aqueon’s fancy band, so if your room hits them, reduce food and fix the heat.
Do not heat the tank to tropical levels so a guppy can move in.
For the longer roommate list, use our guide to what fish can live with goldfish.
Diet: sinking food only
Feed a sinking goldfish pellet or granule, and stop the meal in a few minutes.
Aqueon says goldfish are omnivores. In the wild they eat crustaceans, insects, and plants.
In a tank they gulp air if they feed at the surface, and that air can make them float upside down.
Aqueon’s care guide tells you to soak flake food and skip floating pellets. Feed only what the fish finish in 2 to 3 minutes, once or twice a day.
Hikari’s Saki-Hikari Fancy Goldfish page sets a different clock. It says to feed 2 to 4 times daily, in a few minutes, then remove leftovers.
Our research team laid those two clocks on one sheet. We use Aqueon’s once-or-twice rhythm to cut waste. We use Hikari’s sinking format so the fish do not gulp air.
Hikari lists Saki-Hikari Fancy Goldfish as a sinking daily diet for fancy goldfish, with 45% minimum crude protein, 7.0% minimum fat, and 1.8% minimum phosphorus.
Hikari sells that diet in a 7.0 oz (200 g) bag and a 2.2 lb (1 kg) bag.
Hikari’s Lionhead page lists another sinking fancy diet, with 46% minimum crude protein, 6% minimum fat, and 1.2% minimum phosphorus.
Hikari sells Lionhead in a 3.5 oz (100 g) bag and a 12.3 oz (350 g) bag.
Omega Sea’s page for Omega One Goldfish Pellets Large Sinking lists 35% minimum protein, 10% minimum fat, and packs of 3.8 oz and 7.5 oz.
Aqueon’s Goldfish Granules page says the granules sink and measure about 1.5 mm. It names pearlscales on the ideal-use list.
That page lists 3 oz and 5.8 oz packs and does not publish a guaranteed analysis.
Our research team compared those four labels side by side. Listed minimum protein runs from 35% on Omega One to 46% on Hikari Lionhead. That 11-point spread is a label fact, not a rank.
| Product | Form | Crude protein (min) | Crude fat (min) | Crude fiber (max) | Listed pack sizes |
|---|---|---|---|---|---|
| Saki-Hikari Fancy Goldfish Color Enhancing | Sinking pellet | 45% | 7.0% | 3.0% | 7.0 oz (200 g), 2.2 lb (1 kg) |
| Hikari Lionhead | Sinking pellet | 46% | 6% | 5% | 3.5 oz (100 g), 12.3 oz (350 g) |
| Omega One Goldfish Pellets Large Sinking | Sinking pellet | 35% | 10% | 3% | 3.8 oz, 7.5 oz |
| Aqueon Goldfish Granules | Sinking granule, 1.5 mm | Not listed | Not listed | Not listed | 3 oz, 5.8 oz |
Use one sinking staple as the daily meal. Rotate a second sinking food if you want variety. Aqueon allows frozen or live foods as treats, not as the whole diet.
If a fish floats after a meal, stop floating food the same day. Shorten the next feeding to what it can finish in 2 minutes.
Tank mates that match the body type
Keep pearlscales with other fancy goldfish of like size, not with fast single-tails.
Aqueon says goldfish are gregarious. They like company of their own kind. The same care guide says commons, comets, and shubunkins can become too boisterous for smaller fancy goldfish.
That is the roommate split this page uses:
- Fancy with fancy: pearlscale, fantail, oranda, ryukin, ranchu, lionhead, moor.
- Single-tail with single-tail: common, comet, shubunkin. Keep those fish out of a pearlscale tank.
Aqueon says to avoid fin nippers and other rowdy fish. It also says an unheated tank needs cool-water roommates, not tropical fish.
Do not add a second species to “clean up” leftover food. Extra mouths raise waste and do not replace a water change.
If you want the longer cool-water list, read what fish can live with goldfish.
This page stays on fancy-to-fancy pairs.
Add a roommate only after the first fish already lives in a tank that meets the 20-and-Sink gallon math. Two adults need 30 gallons on our rule. Three adults need 40 gallons.
Aqueon says goldfish scatter eggs and give no care after spawning. Eggs hatch in 48 to 72 hours if you move them.
Extra fry raise the waste load fast. Remove eggs if you are not ready to raise young.
Color and scale changes
New color shifts are a water check first, not a new goldfish type.
Pearlscale “pearls” can rub off on rough rock, which is a décor problem and not a reason to add medicine.
New black patches after a waste spike often mean healing skin, so test the water first. Then follow why your goldfish is turning black.
A slow fade to pale or white uses the same pigment cells, so use why goldfish turn white for that path.
Aqueon says all fancy types are still Carassius auratus. Color is not a compatibility test. A calico pearlscale and an orange pearlscale follow the same gallon and food rules.
If the fish stops eating or cannot stay upright, stop guessing at home. Take a fresh water sample and the fish to a clinician who treats fish.
FAQ
How big of a tank does one pearlscale goldfish need?
One adult pearlscale needs at least 20 gallons on this page’s rule. Aqueon’s care guide lists 10 gallons per adult fancy goldfish, which is a lower floor. We start at 20 gallons because Aqueon’s 20 Long is the smallest rectangle on that chart with a 30¼-inch swimming length.
What should I feed a pearlscale goldfish?
Use a sinking goldfish pellet or granule, not a floating pellet. Hikari lists 45% minimum protein on Saki-Hikari Fancy Goldfish and 46% on Hikari Lionhead. Omega Sea lists 35% minimum protein on Omega One Goldfish Pellets Large Sinking.
Can pearlscale goldfish live with other goldfish?
Yes, if the roommate is another fancy goldfish of like size and the tank already meets the gallon math. Aqueon warns that commons, comets, and shubunkins can out-swim smaller fancy fish. Do not mix a pearlscale with a comet.
Can a pearlscale goldfish live in a bowl?
No. Aqueon says goldfish should never live in bowls, small tanks, or any unfiltered container. Aqueon’s Mini Bow 5 lists 55 pounds when full and fails the 20-gallon rectangle rule.
How often should I feed a pearlscale goldfish?
Follow Aqueon’s clock: feed once or twice a day, and only what the fish finish in 2 to 3 minutes. Hikari’s Saki-Hikari page allows 2 to 4 feedings a day in a few minutes. We keep the lower Aqueon count so leftover food does not pile up.
What temperature do pearlscale goldfish need?
Keep them in Aqueon’s fancy band of 68°F to 74°F. Aqueon’s comet band of 60°F to 70°F is for single-tails, not for this body type. Hikari says to cut food if the water stays below 50°F or above 86°F.
How long do pearlscale goldfish live?
Aqueon’s care guide says goldfish can live over 20 years with proper care. That number is for the species, not a pearlscale-only trial. A tight tank or a bowl cuts that clock short.
