The double bell siphon
The bell siphon, re-engineered.
A new technology that is simply more reliable.
0
Moving parts. Gravity and air pressure do the work.
3
Bell options, matched to common aquaponic needs
30 min
Typical flood and drain cycle in a 1000 L bed.
10 min
To install. Drop it over the drain and go.
How it works
Flood. Trigger. Drain. Repeat.
A bell siphon is a self-operating drain. It turns your pump’s constant flow into a full flood-and-drain cycle, so roots alternate between nutrient-rich water and fresh air. No timer, valve, or electricity needed. Three nested pipes do the work: a standpipe, a sealed bell over it, and a drilled media guard around both.
01
Fill
Your pump fills the grow bed. Water rises around the bell while the standpipe holds the level.
02
Siphon Triggers
Once water tops the standpipe, it pulls the air out of the bell and the siphon starts on its own.
03
Drain
The bed empties fast into the fish tank. Air breaks the siphon at the bottom, and the cycle starts again.
Why a double bell
Starts every time. Drains all the way.
All bell siphons stop cycling if the flow rate is too high or too low. Our patented double-bell design increases the maximum flow rate by 37% and decreases the minimum flow rate by 25%. Your system will keep cycling under a wider range of conditions.
- Fully automatic. No timers, sensors, or electronics.
- Empties the bed completely, so roots get oxygen between floods.
- Reliable startup down to 3 L/min of flow.
- Media guard included to keep gravel and roots out.
Operating range results
12″ tall, 3″ bell · bench tested
Versus DIY
You could build one. Here is why people don’t.
| Siphona | DIY PVC siphon | |
|---|---|---|
| Siphon Limits | Coming Soon | Depends on the build |
| Sizing | 12in siphon kits | Trial and error |
| Build quality | Prototypes available | Hand-cut and glued |
| Setup time | Coming Soon | An afternoon, plus tuning |
| Support | Direct from the people who designed it | Forum threads |
From the journal.
Questions
Good to know.
Still unsure which size fits your system? Send us your bed dimensions and we’ll tell you.
What is a bell siphon?
A simple device that sits over the drain in a grow bed. It lets the bed fill to a set level, then drains it all at once using a siphon. It’s what makes flood and drain aquaponics work without a timer.
Which size do I need?
It depends on your bed depth and pump flow. [Short sizing rule, e.g. “Compact for beds under 00 cm, Standard for 00–00 cm, Large above that.”]
Will it fit my existing grow bed?
[Describe the fitting: bulkhead size, thread, or adapter included.]
Do you work with schools?
Yes. We offer classroom pricing and lesson resources. Get in touch for a quote.
Set it once. Let the water do the rest.
Ships in 7-10 business days. 30-day returns.