We have recently moved our Cylinder Loop from aarke.com to aarke.us. To access your existing subscription, please begin by creating a new account using the same email you used when you signed up. You can manage your subscription from your account portal. You will now be able to make changes to your address, payment method, print your return label, and order a new exchange box.

We're so sorry to hear that! If you mailed in your empty cylinders and haven't received a notification or refills within 7 business days, contact us for assistance.

A few reasons for this include an issue with the post office scanning your label or an issue with your subscription payment method.

We will be able to initiate a new exchange order on your existing subscription.

Yes. You will be asked to create an account at checkout to proceed with your order. This is required to enable us to securely store your payment method and automatically charge it when you decide to exchange your cylinders in the future.

Purchases of CO2 made from Amazon are not part of the subscription service. To begin a subscription, please sign up on our CO2 product page by filling out the questionnaire with your zip code and the amount of cylinders you own to generate a new subscription order.

No. You will need to send back two cylinders in your return box every time.

If you only return 1 cylinder we will need to charge an additional $9 ($51 total) for the missing exchange canister.

We recommend having a 3rd cylinder to have while you're waiting on your replacements.

Yes, The Cylinder Loop is an on-demand subscription service. This means that after you sign up for the service and place your first order, we securely save your payment details. This way, you won’t have to place any additional orders on our website when you want to exchange your empty cylinders.

The difference from a traditional subscription model is that you (and only you) control how often your cylinders are exchanged. You will only get charged after you send us the empty cylinders – and the full cylinders are on their way to you. Only you decide when this happens depending on your sparkling water consumption.

If you do not return your cylinders to exchange, you will not be charged. There are no monthly or yearly fees -- you only pay for what you use.

There is no specific timing for a cylinder exchange in The Cylinder Loop. It depends entirely on how often you carbonate and drink sparkling water.

In The Cylinder Loop, only 2 empty cylinders can be exchanged at a time with our exchange box. We recommend having 3 cylinders in total at home, so you can still have one in your Carbonator, while you're waiting for the other two to be exchanged.

The water will no longer become bubbly when you’re going through the usual carbonation steps. Before exchanging the empty cylinder, or putting it into the exchange box, you can double check that it is completely empty by depressing the center pin with a spoon. Any remaining CO₂ will be removed then.

There’s no need to manually place an exchange order on our website. The Cylinder Loop exchange works like this:

1. Once you have two empty cylinders, you screw the valve caps the cylinders came with back on – and put the cylinders back in the box they arrived in (the exchange box).

2. On the back of the box, place the included shipping sticker over the existing shipping label. Then put the box with your two empty cylinders in your mailbox or give it to a USPS carrier.

3. Once we receive a confirmation that you have posted empty cylinders, we will automatically charge you $42.00 for the 2 full exchange cylinders and send you a tracking number for them. That’s it! The full gas cylinders will be delivered to you with FedEx fast shipping.

Usually, yes. But it depends on the condition and model of your gas cylinder. We accept standard 400-425g (14.5 oz) /60L gas cylinders approved for use with sparkling water makers.

We do not accept cylinders that are damaged. We do not accept the Soda Stream Quick Connect cylinders with the pink ring.

In all other cases, yes – you can exchange your empty cylinder from another brand to get started with The Cylinder Loop.

For The Cylinder Loop, FedEx will send out the full cylinders to you, while USPS sends the empty ones to us.

Please note that if you order the Carbonator together with the start exchange box and CO2 cylinders, the parcels might arrive at different times due to the packages being sent from different locations.

Since the cylinders classify as hazardous goods, they must be shipped with ground transportation which effects the delivery time. Once USPS confirms to us that they have your exchange cylinders, we initiate your cylinder order. The delivery time will then be 2-5 days. When this new order is on its way, you will receive an e-mail and a tracking link.

Please enter your ZIP-code in the questionnaire on a Carbonator or the CO2 product page.

If not, please know that we’re working on getting The Cylinder Loop available in the entire US as soon as possible. Please check back soon!

We are unable to ship CO2 to Hawaii, Puerto Rico, and Alaska.

It’s easy. Just stop giving the exchange box with empty cylinders to USPS and you will never be charged for an exchange again.

If you no longer want us to store your payment information, contact us and we will delete your data from our system. If you are a registered user, your account, purchase history and quick checkout address information will also be deleted, since they are connected.

No. Aarke gas is not a discounted item and discount codes will not be applied to gas in your cart.