Blubber Cove Long Aquarium Tunnel – Buried Shrimp Breeding Cave (Left or Right)

The Blubber Cove Long Aquarium Tunnel is a long, slim hidden tunnel designed to disappear under your substrate. Where most aquarium caves are bulky shells that dominate the tank, this one runs flat and narrow along the bottom — burying invisibly under sand or gravel to create a long underground tunnel system that shrimp, fry and corydoras claim as breeding territory. Choose left-facing or right-facing to match your tank's flow direction. UK 3D-printed in our Northumberland workshop from aquarium-safe PETG.

Why a long buried tunnel works for breeders

Shrimp and small fish breed best when they have enclosed, low-flow territory away from tankmates. A long buried tunnel gives them that — multiple internal feet of dark, sheltered space where berried shrimp can hide and fry can grow without being eaten. Unlike a single-chamber cave, the tunnel length means a whole colony can claim it at once. Established breeders use this kind of setup specifically to increase fry survival rates.

Why left or right?

The tunnel openings face one direction. Pick the variant that matches your tank — if your filter outflow runs left-to-right, choose right-facing so the tunnel entrance faces against the flow (calmer water inside the tunnel). For breeding tanks specifically, this small detail matters: shrimp avoid high-flow entrances. The mirror variants exist so you don't have to compromise on placement.

Features

• Long thin tunnel shape — runs along the tank bottom, fully buries under substrate
• Left or right facing variants — match your tank flow direction
• Hidden once buried — only the tunnel opening shows
• Designed for shrimp breeding tanks, fry grow-outs and planted nano setups
• Smooth interior — safe for delicate fins, shrimp moults and tiny fry
• 3D-printed in Northumberland, UK from aquarium-safe PETG
• Encourages natural foraging and burrow-style hiding behaviour

Specifications

• Material: Aquarium-safe PETG plastic
• Standard size: 174 × 73 × 62 mm (tunnel opening 75 mm wide)
• Large size: 222 × 89 × 80 mm (tunnel opening 93 mm wide)
• Variants: Standard-Left, Standard-Right, Large-Left, Large-Right
• Placement: Buried under substrate along the tank bottom
• Colours: Black, White, Marble Effect, Moss Green, Sand
• Made in: Northumberland, United Kingdom
• Brand: Blubber Cove

Suitable for these setups

• Neocaridina and Caridina shrimp breeding tanks
• Corydoras spawning and fry grow-out tanks
• Planted nano communities (chili rasbora, ember tetra, CPD)
• Endler and guppy fry grow-out tanks
• Kuhli loach habitat enrichment
• Aquascapes where decor needs to be invisible

How to set it up for breeding

1. Place the tunnel along the back or side of the tank, opening facing away from filter flow
2. Cover the top and sides with substrate (sand or fine gravel works best)
3. Leave the entrance opening clear
4. Plant moss carpets or low-light plants directly on top to disguise further
5. Within days, shrimp and bottom-dwellers will claim it as a breeding territory

Frequently asked questions

How does this differ from your other underground cave?

Shape and length. Our Underground Corner Cave is a square 135×135mm shell designed for the back 90° corner. This one is a long thin 174×73mm tunnel designed to run along the tank bottom. Choose this for shrimp breeding tanks where you want longer hidden territory; choose the corner cave for general nano-tank shelter in the back corner.

Which direction (left or right) should I choose?

Look at your filter outflow direction. If water flows left-to-right across your tank, pick right-facing so the tunnel opens against the flow (calmer interior). If water flows right-to-left, pick left-facing. For breeding tanks specifically, lower interior flow improves fry survival.

Will the substrate weight crush it?

No — PETG is rigid and the tunnel is engineered to take substrate load. You can cover it with several centimetres of sand or gravel without warping.

Is it safe for shrimp colonies?

Yes. PETG is shrimp-safe (no copper, no leaching). The smooth interior won't catch moults. The long enclosed space is specifically suited to breeding colonies — berried females retreat inside to give birth.

Will fry actually grow inside?

Yes — shrimplets, corydoras fry and small livebearer fry use the tunnel as a grow-out hiding zone away from larger tankmates. Many buyers report visible fry survival increases after adding one.

Can I plant on top?

Yes — low-light plants like cryptocoryne, moss carpets or anubias work beautifully directly above the buried tunnel. Roots grow around the structure.

How do I clean it?

Most buyers leave it buried permanently — debris washes through naturally with water changes. If you want to deep-clean, lift gently from substrate, rinse in tank water, and reposition. Never use soap or detergent.

Why buy from Blubber Cove

Original aquascaper-designed pieces, 3D-printed to order in our Northumberland workshop in aquarium-safe PETG. Small-batch production, every piece checked before it ships. No imports, no drop-shipping. Free UK delivery over £30.