Litres, watts and litres per hour — calculated, not guessed.
You write the volume once and we tell you which filter, which heater and how many lumens it needs. Plus which species it suits and what to do in the first two hours.

Most taken
Ceramic mug
Ceramic vase
Merino scarf
Oak side chair
Work apron
Woven basket
Wool throw
What you need for it to work from day one
The numbers below are calculated for the volume written above, not copied off a box. An undersized filter is the number one cause of cloudy water.
Calculated for 120 litres
- External filterIt turns the whole volume over five times an hour. 600l/h Essential
- Heater with thermostatHalf a watt per litre holds 25° in a room at 20°. 60W Essential
- LED lightFor plants that actually grow, not just to see the fish. 3600lm Essential
- Air pumpOptional with a good filter, essential in summer, when water holds less oxygen.
If you keep messy fish, move the filter flow up one step.
How it travels
The oxygen bag goes into a polystyrene box with a warm or cold gel pack, depending on the weather. We ship Mondays and Tuesdays, so nothing sits in a depot over the weekend.
3days in which to report any problem
- 01A 24-hour fastUnfed, the water in the bag stays clean the whole way.
- 02A pure oxygen bagDoubled, with the corners tied off so nothing gets caught in them.
- 03A polystyrene boxWith a gel pack: warm in winter, cold in summer.
- 04Next-day courierWe ship Mondays and Tuesdays. Never on a Thursday.
- 05A photo on openingTake a photo before you open the bag: it is all we need for a replacement.
Calculated equipment
From the litres of your own tank.
Written compatibility
Only what we have kept together ourselves.
Live delivery
An oxygen bag in an insulated box.
The first two hours
Step by step, with the minutes.
What arrives this week
An email on Thursday, with the newly arrived fish and plants.



