In your tank · Available now

The Bubble

$39 Made to order

A clear dome that sits on the floor of your tank and holds a pocket of air. A real plant grows inside it. The tank water feeds it.

5 inches tall, 3.5 inches wide. For tanks of 5 gallons and up.
Runs on a standard aquarium air pump and airline.
Flood and drain, driven by a reverse bell siphon. No moving parts.
A suction cup on the bottom holds it down on the tank floor.
Grows micro herbs, small greens, small houseplants.
Adds air to the tank day and night, and its leaves never take oxygen from your fish.

Made to order. Checkout is secure and handled by Shopify.

You'll need an air pump. The Bubble runs on a standard aquarium air pump and airline, which many tanks already have. They are not in the box. See the Air Kit

Height: 5 in (127 mm)
Width: 3.5 in (90 mm)
Tank size: 5 gal and up
Air: Standard aquarium air pump
Airline: 3/16 in standard tubing
Held down by: Suction cup on the bottom
In the box: Dome, base, siphon, gravel bed

How it works

It breathes. On a loop.

Air in
Your aquarium air pump sends a slow stream of air into the dome. The air collects under the dome and pushes the water in the gravel down.
Roots breathe
The water drops below the gravel. For a while the roots sit in damp air, which is what roots want.
Water returns
When the air reaches the reverse bell siphon in the base, the siphon trips and lets it all out in one breath. Tank water rises back into the gravel and stops there: it wets the roots and never reaches the leaves. Then it starts again.

Cutaway of the base showing the reverse bell siphon: a standpipe under a bell cap

The clever part

A siphon, running backwards.

A bell siphon normally drains water out of a grow bed once it fills. Ours sits underwater and does the opposite: it lets air out once the dome fills with it.

It is one printed part with no valve, no float and nothing to wear out. It was the first thing we got working, and the reason the rest exists.

Goes with