Natural Color Volcanic Substrate Red 2-4mm 5kg

£9.99 Free UK delivery

Red · 2–4mm is currently sold out

Same day despatch before 3pm *

Free tracked 2–3 days · 1–2 days £4 · Next day £6

Free UK delivery
30-day easy returns
Feefo Platinum Trusted Service 2026
American Express Apple Pay Google Pay Maestro Mastercard PayPal Shop Pay
Red · 2–4mm £9.99

About the Natural Color Volcanic Substrate Red 2-4mm 5kg

Bigger tanks want a chunkier bed so the lower layers do not compact and go stale. At 2-4mm this volcanic red ceramic substrate keeps air and water moving through, while still letting plant roots run right through it - and it is perfect for aquarium planted and tropical fish tanks.

Roots penetrate the material easily and spread right through the bed, which is what a planted tank needs from its floor.

Specification

  • Size: 2-4mm
  • Colour: Volcanic Red
  • Material: Ceramic
  • Aquarium substrate for aquarium plants
  • Good water and air penetrability
  • Great substrate pebble for aquarium fish tank
  • Supplied in 5kg, 10kg, 20kg, 30kg, 40kg and 60kg packages (please select)

Working out how much substrate you need

To reach a Two Inch (2") gravel depth in your fish tank, measure up and follow these three steps:

  1. Multiply tank LENGTH by tank WIDTH in inches. Worked example: 47" Inches x 19" Inches = 893
  2. Divide that figure by 10. Worked example: 893 / 10 = 89.3
  3. Divide by 2.2 to convert to kilogrammes. Worked example: 89.3 / 2.2 = 40.5 KG REQUIRED

Rough guide for a 2" substrate / gravel depth

  • 60cm / 2ft TANK = 25 kg
  • 80cm / 2.6ft TANK = 30kg
  • 100cm / 3.3ft TANK = 35 kg
  • 120cm / 4ft TANK = 40 kg

Treat these as approximates - you may well want a deeper or thinner layer of substrate / gravel.

Delivery & returns
Tracked 2–3 daysFREE
Tracked 1–2 days£4.00
Courier next day£6.00
30-day returnsEasy online returns

Order before 3pm Monday–Friday for same-day despatch. We deliver to the UK mainland, Northern Ireland and the Isle of Man. Full delivery & returns policy

Frequently asked questions

What grain size is this red substrate?

It is 2-4mm.

What pack sizes can I order?

It is supplied in 5kg, 10kg, 20kg, 30kg, 40kg and 60kg packages, chosen from the options.

What is the substrate made of?

Ceramic, in a volcanic red colour.

Is it good for aquarium plants?

Yes, it is an aquarium substrate for plants and roots easily penetrate and spread throughout it.

Does it allow water and air through?

It has good water and air penetrability.

How much do I need for an 80cm tank?

Roughly 30kg gives a 2 inch depth in an 80cm / 2.6ft tank.

Compare the range

Volcanic Aquarium Substrate 5kg – 4 options

OptionPriceAvailability
Black · 1–2mm £18.99 Sold out View
Black · 2–4mm £15.83 Sold out View
Red · 1–2mm £9.99 Sold out View
Red · 2–4mm Viewing £9.99 Sold out

Specifications & downloads

Model: XF20701B

You might also like

Recently viewed