Is this a complete substrate or a cap?

It works as a standalone substrate. Many keepers use it alone for rooted plants, or cap it with sand or gravel for a finer top layer.

Does it need rinsing before use?

Yes. Rinse in a bucket until the water runs mostly clear, since the bag carries fine dust that clouds a new tank.

Will it raise or lower my pH?

The maker says it buffers and softens water over time. The effect is mild and depends on your tap water, so test pH before and after setting up.

How much area does a 10 lb bag cover?

Coverage depends on depth. For a typical 2-inch bed it suits a small tank; larger tanks need two or more bags.

Is it safe for shrimp and bottom dwellers?

The grains are rounded volcanic stone, not sharp gravel, so corydoras and shrimp can forage on it. Rinse well first to remove dust.

Do I still need fertilizer?

Yes for heavy root feeders. The substrate holds nutrients poorly compared with aquasoil, so use root tabs and liquid fertilizer.

What do buyers say about the Imagitarium Japanese Volcanic Substrate, 10 lbs.?

Rated 3.8 out of 5 from 4 ratings.

Where can I buy the Imagitarium Japanese Volcanic Substrate, 10 lbs.?

3 stores we checked sell it, including Walmart, Petco, Lowe's.

Imagitarium Japanese Volcanic Substrate, 10 lbs.

Best price now

$34.99at WalmartChecked 5 h ago

Compared across 3 stores. Prices are checked against each store and labelled with when.

Visit Walmart

Imagitarium Japanese Volcanic Substrate, 10 lbs.

Best price now

$34.99at WalmartChecked 5 h ago

Compared across 3 stores. Prices are checked against each store and labelled with when.

Visit Walmart

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Price facts

Lowest price today: $34.99 at Walmart (checked Nov 10, 2026).
Checked at 3 stores.

Our take on the Imagitarium Japanese Volcanic Substrate, 10 lbs.

A 10 lb bag of porous volcanic-stone pellets in mixed 3mm and 5mm sizes, sold as a planted-aquarium substrate. The porous grains give roots something to grip and host bacteria, and the manufacturer says it softens water and buffers pH over time. It suits planted-tank keepers who want a natural, inert-looking base rather than a bright aquasoil. Compared with branded aquasoils it offers less nutrient loading and no ammonia spike, but also less initial feeding for heavy root feeders.

Best forPlanted freshwater tanksRooted plants like swords and cryptsKeepers who want a natural dark baseLow-tech setups with light fertilizing

Pros

Porous grains anchor roots and host beneficial bacteria
Mixed 3mm and 5mm sizes suit small and large root systems
Volcanic stone is inert and won't cloud water like soil
Claimed pH buffering and water softening
Rinses to a natural dark look that suits most scapes

Cons

Little nutrient content compared with aquasoils, so root tabs help
Lighter than gravel and can shift when disturbed
Needs thorough rinsing; fine dust at first
pH buffering effect is modest and varies by tap water

Imagitarium Japanese Volcanic Substrate, 10 lbs. prices at every store

WalmartNew
In stockSold by Petco Animal Supplies, Inc.Returns: Sold by a Walmart Marketplace seller; returns go to the seller under the seller's returns policy.
$34.99Free shippingChecked 5 h ago
Visit Walmart
Lowe'sNew
In stock
$34.99Checked 5 h ago
Visit Lowe's
PetcoNew
In stock
$34.99+ $6.99 shippingChecked 5 h ago
Visit Petco

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Imagitarium Japanese Volcanic Substrate, 10 lbs. price history

Lowest price we've seen: $34.99 on Nov 10 at Petco. Tracked across 2 stores since Nov 10.

What reviewers say

Planted-tank keepers generally find it a decent, affordable porous base that holds roots well and looks natural. Some report dust and floating grains after rinsing, and note that heavy root feeders need added fertilizer.

What people mention

Root gripPraisedOwners say stems and rooted plants stay put in the porous grains.
DustCriticisedSeveral mention fine dust that needs repeated rinsing before filling.
Floating grainsMixedA few grains float initially and settle after soaking.
NutrientsMixedKeepers note it feeds little on its own and add root tabs.
PH bufferingMixedSome see a small pH shift; others find no measurable change.

About the Imagitarium Japanese Volcanic Substrate, 10 lbs.

The Imagitarium Japanese Volcanic Substrate is a nutrient-dense substrate ideal for planted aquariums. It includes a blend of 3mm and 5mm pellets, making it the ideal shape and sizing for small and larger root systems to anchor and grow. Over time, this substrate will aid in water softening and pH buffering.

Specifications

Weight (lb): 10.0Source
Material: Volcanic StoneSource
Animal type: FishSource
Weight: 5.04 lbSource

Questions and answers

Is this a complete substrate or a cap?: It works as a standalone substrate. Many keepers use it alone for rooted plants, or cap it with sand or gravel for a finer top layer.
Does it need rinsing before use?: Yes. Rinse in a bucket until the water runs mostly clear, since the bag carries fine dust that clouds a new tank.
Will it raise or lower my pH?: The maker says it buffers and softens water over time. The effect is mild and depends on your tap water, so test pH before and after setting up.
How much area does a 10 lb bag cover?: Coverage depends on depth. For a typical 2-inch bed it suits a small tank; larger tanks need two or more bags.
Is it safe for shrimp and bottom dwellers?: The grains are rounded volcanic stone, not sharp gravel, so corydoras and shrimp can forage on it. Rinse well first to remove dust.
Do I still need fertilizer?: Yes for heavy root feeders. The substrate holds nutrients poorly compared with aquasoil, so use root tabs and liquid fertilizer.
Where is the Imagitarium Japanese Volcanic Substrate, 10 lbs. cheapest?: At Walmart, for $34.99, as of our latest check.
What do buyers say about the Imagitarium Japanese Volcanic Substrate, 10 lbs.?: Rated 3.8 out of 5 from 4 ratings.
Where can I buy the Imagitarium Japanese Volcanic Substrate, 10 lbs.?: 3 stores we checked sell it, including Walmart, Petco, Lowe's.