29 gallon vs 40 gallon breeder

The 29 gallon is 30 x 12 x 18 inches, a 20 long made taller. The 40 breeder is 36 x 18 x 16, wider in both directions. The breeder fits more kinds of fish; the 29 fits more rooms.

29 Gallon

40 Gallon Breeder

Side by side

	29 Gallon	40 Gallon Breeder
Dimensions (L x W x H)	30 x 12 x 18 in	36 x 18 x 16 in
Footprint	2.5 sq ft	4.5 sq ft
Water, to the brim	28.1 gal	44.9 gal
Empty weight	about 42 lb	about 54 lb
Filled, with gravel	about 323 lb	about 457 lb
Floor load	about 129 lb/sq ft	about 102 lb/sq ft
Heater	150 W	200 W
Filter flow	116 to 174 gph	160 to 240 gph
Stand and lid	30 x 12 in	36 x 18 in

Pick the 29 gallon if

Your spot is 30 inches wide, which rules out the 36 inch breeder.
You keep small schooling fish and want height for plants and gouramis.
You already have a 30 x 12 stand from a 20 long. The 29 uses the same one.

Pick the 40 gallon breeder if

You want bottom fish, dwarf cichlids or two fancy goldfish. The 18 inch depth front to back is the difference.
You like scaping: the breeder is the easiest standard tank to aquascape.
You can give it 36 x 18 inches of floor and a stand built for about 460 lb.

What fits in one but not the other

Fit the 40 gallon breeder but not the 29 gallon: Angelfish.

From the popular fish we checked against the Seriously Fish footprints.

More of the same fish

	29 Gallon	40 Gallon Breeder
Neon tetra	31	50
Ember tetra	47	76
Guppy	15	25
Harlequin rasbora	21	33
Zebra danio	19	30
Cherry barb	19	30

Mixes that work in the 29 gallon

Cardinal tetras and bronze corydoras
12 × Cardinal tetra, 6 × Bronze cory.
92% stocked
Honey gouramis with harlequin rasboras
4 × Honey gourami, 8 × Harlequin rasbora.
61% stocked
Platies and panda corydoras
6 × Platy, 6 × Panda cory.
63% stocked
Guppies with a bristlenose pleco
8 × Guppy, 1 × Bristlenose pleco.
79% stocked
A pair of kribensis with ember tetras
2 × Kribensis, 10 × Ember tetra. This tank is under the recommended minimum for Kribensis (a 24 x 15 in footprint).
47% stocked

Mixes that work in the 40 gallon breeder

Bolivian rams with rummy-nose tetras
2 × Bolivian ram, 12 × Rummy-nose tetra.
50% stocked
Two fancy goldfish
2 × Fancy goldfish.
81% stocked
Cherry barbs, kuhli loaches and honey gouramis
8 × Cherry barb, 6 × Kuhli loach, 4 × Honey gourami.
89% stocked
A big school of neon tetras with corydoras
20 × Neon tetra, 8 × Bronze cory.
79% stocked
Platies, mollies and a bristlenose pleco
6 × Platy, 4 × Molly, 1 × Bristlenose pleco.
59% stocked

Try your fish in either tank

Common questions

Which is bigger, a 29 gallon or a 40 gallon breeder?

The 40 gallon breeder holds 44.9 gallons to the brim against 28.1 for the 29 gallon, and its footprint is 36 x 18 inches against 30 x 12.

Do a 29 gallon and a 40 gallon breeder use the same stand?

No. The 29 gallon needs a 30 x 12 inch stand and the 40 gallon breeder a 36 x 18 inch one.

How much more does a 40 gallon breeder weigh?

About 134 lb more when filled: roughly 457 lb against 323 lb with water and two inches of gravel.

Is a 40 gallon breeder a good beginner tank?

Yes. It is the most forgiving standard size: enough water to stay stable, a footprint that suits bottom fish and dwarf cichlids, and still light enough for an ordinary stand built for aquariums.

Can a 29 gallon use a 20 gallon long stand?

Yes. Both have a 30 x 12 inch footprint, so they share stands and lids. Check the stand is rated for the extra weight: about 323 lb filled against 229 lb.

Gear for a 29 gallon

Searches on Amazon for the right size. Check the tank size or flow rating on the listing before you buy.

Heater, 150 WSized for a normal room.Filter, 116 to 174 gphA hang-on-back or sponge filter works.Stand, 30 x 12 in or largerMust support the whole bottom frame.Lid or hood, 30 x 12 inKeeps fish in and slows evaporation.Water test kitTracks ammonia, nitrite and nitrate.Water conditionerRemoves chlorine from tap water.

As an Amazon Associate we earn from qualifying purchases. Prices and stock are Amazon’s.

Gear for a 40 gallon breeder

Searches on Amazon for the right size. Check the tank size or flow rating on the listing before you buy.

Heater, 200 WSized for a normal room.Filter, 160 to 240 gphA hang-on-back or sponge filter works.Stand, 36 x 18 in or largerMust support the whole bottom frame.Lid or hood, 36 x 18 inKeeps fish in and slows evaporation.Water test kitTracks ammonia, nitrite and nitrate.Water conditionerRemoves chlorine from tap water.

As an Amazon Associate we earn from qualifying purchases. Prices and stock are Amazon’s.