EHEIM CO2 solenoid valve for aquariums, night-time shut-off, 230 or 24 V

Regular price $69.00
Regular price Sale price $69.00
$23.00 × 3 with no fees

The EHEIM CO2 solenoid valve shuts off the CO2 supply when the lighting goes out: plants no longer use it at night, and the fish are not at risk of running short of oxygen because of it.

230 V version for a programmable socket, or 24 V for connected EHEIM devices.

Ref. H6064210·pH and CO2 control
Version : 230 v, prise secteur
Customer support 7 days a week by email
Delivery within 2 to 15 business days
100 % secure payment
Visa Mastercard American Express PayPalCartes Bancaires Apple Pay Shop Pay Bancontact EPS KlarnaMobilePay

The summary

  • Which version: 230 V mains, or 24 V for EHEIM appliances.
  • What it is for: cutting off the CO2 at night, when the plants no longer consume it.
  • Installing it: between the regulator and the bubble counter, 4/6 mm pipe.
  • What is supplied: the solenoid valve, and for the 24 V a non-return valve.

CO2 by day for the plants, oxygen at night for the fish

The EHEIM CO2 solenoid valve cuts off the CO2 supply when the lighting goes off, because plants no longer consume it at night and the excess gas would cause the pH and oxygen to drop. It is available in 230 V for use with a programmable socket, or in 24 V for connected EHEIM devices, and fits a 4/6 mm pipe.

Plants only absorb CO2 when they are lit. At night, they stop photosynthesising and respire like the fish: they consume oxygen and release CO2 as well. If the cylinder keeps injecting gas during this time, the CO2 builds up, the pH drops and the water loses oxygen, just when it is already at its scarcest. The EHEIM CO2 solenoid valve shuts off the CO2 supply when the lights go out and reopens it in the morning, so your setup follows the plants' rhythm.

🔌 Two versions depending on the installation

The 230 V version plugs into a mains socket and opens as soon as it receives power. If you plug it into the same programmable socket as the lighting, or into a separate timer, it automatically follows your schedule: the CO2 starts with the light and stops with it. It is the simplest solution if your setup is a standard one, with no connected EHEIM device, and it suits any regulator, for disposable cylinders as well as refillable ones.

The 24 V version has a connector specific to EHEIM, and it is intended for you if your aquarium is already fitted with connected EHEIM devices. It plugs into the powerLED+ light bar and is controlled with the LEDcontrol+e, which shuts off the CO2 at the programmed sunset and reopens it at dawn, or with the pHcontrol+e, which opens and closes it according to the measured pH. It can also work on its own on a timer, with the 20 W powerLED power supply sold separately. It is supplied with a non-return valve and a 1.5 m cable.

A non-return valve on the pipe

Without a valve, water from the tank can flow back up the pipe when the pressure drops, and reach the solenoid valve or the regulator. Fit a non-return valve on the pipe, before the diffuser, and replace it if it hardens over time.

🔧 Installing and checking

The solenoid valve is fitted between the regulator and the bubble counter, on a 4/6 mm CO2 pipe. Before putting it into service, test it without CO2: plug it in and check that it opens and closes with the socket or device that controls it, a faint click signalling each change. Then check the fittings for leaks with a little soapy water, with the cylinder open. A solenoid valve that no longer closes completely is easy to spot, because the bubble counter keeps going at night. Finally, keep the valve dry, above the water level.

A timer for the 230 V version

A daily timer plugged in between the socket and the 230 V solenoid valve opens and closes it each day at the times you choose, for example 1 hour before the lighting comes on. Your CO2 then reaches its useful level when the light arrives, and it shuts off before night.

Programmable socket

The 230 V version follows the lighting timer.

powerLED+ light bar

The 24 V version, ordered with the bar.

pHcontrol+e

The 24 V version, opened according to the pH.

Replacement

The same version as the original solenoid valve.

📋 An example day

Take a 150-litre planted aquarium lit from 10 h to 20 h, with a 500 g disposable cylinder. The 230 V solenoid valve, connected to a timer set from 9 h to 20 h, opens the CO2 1 hour before the lights come on and shuts it off when they go out. Your cylinder is no longer drained during the 13 hours of the night, which noticeably extends its life, and your fish find each morning water that has not built up CO2 while they were resting. If you do not yet have a set-up, the EHEIM pressurised CO2 kit is available in a version with a solenoid valve.

🌱 In aquaponics

In aquaponics, CO2 injection is rare: the fish and bacteria already produce it, and oxygen takes priority over everything else. It is mostly found in heavily planted aquaponic aquariums, where the aim is fast growth of aquatic plants. In that case, the solenoid valve becomes the installation's first safeguard, because the water must never run short of oxygen at night. The article on regulating pH in an aquaponic system gives the target range, from 6.4 to 7.5.

Technical specifications

The essentials

Pipe
CO2 4/6 mm
24 V version
EHEIM connector, 1.5 m cable, non-return valve supplied
230 V version
Mains plug
Water
Soft

To budget for separately

230 V version
A programmable socket
24 V version only
The 20 W powerLED power supply unit
Warranty
Up to 36 months

In the box

  • 1 CO2 solenoid valve, 230 V or 24 V depending on the version chosen
  • 24 V version: 1 non-return valve and 1 1.5 m cable

EHEIM manufacturer compatibility and contents information, checked on 13/10/2026.

Manufacturer and product safety

Manufacturer
EHEIM GmbH & Co. KG
Postal address
Plochinger Str. 54, 73779 Deizisau, Allemagne
Website
eheim.com

Information provided under Regulation (EU) 2023/988 on general product safety.

Which solenoid valve for your setup?

The same valve with two power supplies. What controls it decides.

230 V or 24 V? One answer, and the table highlights the right version.

FeedControlled byPrice
Recommended
230 VYour choice		230 V mainsA programmable socket$69.00
24 VYour choice24 V, EHEIM connectorpowerLED+, LEDcontrol+e or pHcontrol+e$79.00
230 VRecommended
Connection
Feed230 V mains
Controlled byA programmable socket
24 V
Connection
Feed24 V, EHEIM connector
Controlled bypowerLED+, LEDcontrol+e or pHcontrol+e

The 24 V version is supplied with a non-return valve.

Estimate your
delivery time

Delivered to your home by Colissimo or Chronopost, as you prefer at checkout. The exact cost is shown in the basket, according to the total weight of your order.

Frequently asked questions

8 questions

6 key questions, 8 in the detailed view

You may also like

Related articles

Regulating pH in an aquaponics system
Technique

Regulating pH in an aquaponics system

KH holds the pH, and the pH decides the rest. Why it tends to rise, and what you can realistically do to hold it steady.

Read the article

Let us talk about your project

A question about this product or your setup? Our team will answer and advise you.

Email usContact form

Interest-free instalment payments

Offered depending on the cart amount, at checkout.

Delivery in 2 to 15 working days

Depending on the products and shipping sites. Estimate by destination in the estimator on this page.

After-sales service 7 days a week by email or chat

Our team answers all your questions.

Shop responsibly

Become part of the change.