- Sku: 09722
- Vendor: Ocean Nutrition
Ocean Nutrition ON-Disk
Ocean Nutrition ON-Disk is a press-on feeding disk that sticks directly to your aquarium glass with a built-in suction cup. Fish peck at it for hours, getting natural grazing behavior and slow-release nutrition without dumping a cloud of food into the water. Available in Formula One (carnivore) and Formula Two (herbivore), in 10mm small disks for nano tanks or 20mm large disks for big setups.
Stock up on more marine staples from our fish food collection and round out the reef with saltwater fish and live corals.
How It Works
Each ON-Disk has a built-in suction cup. Wet the disk, press it onto the inside of the aquarium glass below the waterline, and watch your fish flock to it. The compressed disk slowly softens, letting fish peck off bite-sized pieces. One disk feeds an average tank for hours, with no leftover food fouling the water.
Features — All Variants
Choose Your Formula & Size
Select a variant in the tab section below for the full individual spec sheet.
| Spec | F1 Small | F1 Large | F2 Small | F2 Large |
|---|---|---|---|---|
| Diet Type | Carnivore | Carnivore | Herbivore | Herbivore |
| Disk Size | 10mm (Small) | 20mm (Large) | 10mm (Small) | 20mm (Large) |
| Tank Size (Best) | Nano – 75 gal | 75+ gal | Nano – 75 gal | 75+ gal |
| Key Ingredients | Krill, squid, fish | Krill, squid, fish | Kelp, spirulina | Kelp, spirulina |
| Target Species | Clowns, wrasses, anthias | Triggers, eels, groupers | Tangs (small), small angels | Tangs, angels, large herbivores |
| Price | $8.99 | $10.99 | $8.99 | $10.99 |
Detailed Variant Specifications
Click a variant below to view its full specification sheet.
Formula One Small · 10mm · Carnivore
The compact carnivore disk for nano reefs and mid-size tanks. Built around krill, squid, and fish proteins for clownfish, wrasses, anthias, dottybacks, and other meat-eating marine community fish. The smaller diameter is easier for tiny mouths and fits in tight rockwork crevices.
| Specification | Value |
|---|---|
| SKU | 09722 |
| Diet Type | Carnivore |
| Disk Size | 10mm (Small) |
| Best For | Nano & mid-size marine tanks |
| Target Fish | Clownfish, wrasses, anthias, dottybacks, gobies, blennies (meat-eating) |
| Key Ingredients | Krill, squid, fish meal, shrimp |
| Application | Press disk to glass via suction cup, submerged |
| Price | $8.99 |
Formula One Large · 20mm · Carnivore
Twice the diameter, designed for 75-gallon-plus marine tanks with larger predators — triggers, eels, lionfish, groupers, large wrasses, and adult angelfish. The bigger disk takes longer for the school to demolish, so even slower or shyer carnivores get their share.
| Specification | Value |
|---|---|
| SKU | 09724 |
| Diet Type | Carnivore |
| Disk Size | 20mm (Large) |
| Best For | 75+ gal marine tanks with larger fish |
| Target Fish | Triggers, eels, lionfish, groupers, large wrasses, predator community |
| Key Ingredients | Krill, squid, fish meal, shrimp |
| Application | Press disk to glass via suction cup, submerged |
| Price | $10.99 |
Formula Two Small · 10mm · Herbivore
The plant-based disk for nano and mid-size reef tanks. Loaded with kelp, spirulina, and marine plant matter for small tangs, juvenile angels, and any herbivorous reef fish. Encourages natural grazing all day instead of one big meal.
| Specification | Value |
|---|---|
| SKU | 09742 |
| Diet Type | Herbivore |
| Disk Size | 10mm (Small) |
| Best For | Nano & mid-size reef tanks |
| Target Fish | Small tangs, juvenile angels, foxfaces, herbivorous blennies |
| Key Ingredients | Kelp, spirulina, marine plant proteins |
| Application | Press disk to glass via suction cup, submerged |
| Price | $8.99 |
Formula Two Large · 20mm · Herbivore
The big herbivore disk for tang-heavy reef tanks. Designed for adult tangs, large angels, foxfaces, rabbitfish, and any saltwater herbivore that needs grazing material throughout the day. Pairs beautifully with weekly nori sheets for variety.
| Specification | Value |
|---|---|
| SKU | 09744 |
| Diet Type | Herbivore |
| Disk Size | 20mm (Large) |
| Best For | 75+ gal tang-heavy reef tanks |
| Target Fish | Tangs (yellow, blue, sailfin, naso), large angels, foxfaces, rabbitfish |
| Key Ingredients | Kelp, spirulina, marine plant proteins |
| Application | Press disk to glass via suction cup, submerged |
| Price | $10.99 |
Which Variant Is Right for You?
F1 Carnivore · 10mm — Nano reefs and community tanks with clowns, wrasses, anthias, and other meat-eaters under 75 gallons.
F1 Carnivore · 20mm — Big-fish tanks: triggers, eels, lionfish, large wrasses. The larger disk feeds more fish for longer.
F2 Herbivore · 10mm — Nano and mid-size reef tanks with small tangs, juvenile angels, or any herbivore in a community setup.
F2 Herbivore · 20mm — Adult tang and rabbitfish tanks. The 20mm disk gives steady grazing for the high metabolic demand of large herbivores.
Recommended Pairings
FAQ
How long does one disk last in the tank?
Anywhere from a few hours to most of a day depending on tank load. Fish typically pick it down to nothing in 4–8 hours, and any remaining piece can be removed or left to fully dissolve overnight.
Will the suction cup come loose?
If pressed onto clean glass, the suction is reliable. We recommend wiping the glass with the disk underwater first to ensure good contact.
Can I use this in a freshwater tank?
The ON-Disk line is formulated for marine fish. Freshwater hobbyists should look at Ocean Nutrition's freshwater formulas or our broader nutrition collection.
Can I feed F1 and F2 together?
Yes — in mixed-diet tanks (e.g. tangs + wrasses), running a Formula One disk and a Formula Two disk at the same time covers both diets without competition at the surface.
Have a question?
Ocean Nutrition ON-Disk
