frequently asked questions

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How many solenoids are in a SE7EN?

In the SE7EN Classic there are a total of four (4) solenoids:

  • Two metabolic O2 solonoids
  • One O2 calibration solonoid
  • One Diluent calibration solonoid

In the SE7EN+ there are a total of three (3) solenoids:

  • One Metabolic O2 solonoid
  • One O2 calibration solonoid
  • One Diluent calibration solonoid
Can I mix Solid State O2 sensor and galvanic O2 sensor in a SE7EN e-module?

Yes, you can if you have a SE7EN + module or an upgraded SE7EN classic module.

Why dosn't my rebreather start?

The fact that nothing is visible on the display does not necessarily mean that the e-module does not start. Test if you can see your e-module as a Bluetooth device on your PC/Mac. If you can, the e-module is running but probably a device is missing, i.e the HUD or display.

When I try to do a software update on my SE7EN via RB Config, it get timeout. What do I do?

If you have a M28, you can try updating your SE7EN through the computer. Follow the instructions in the operating instructions for the M28 which you can find here.

If you don't have a M28 dive computer, disconnect your SE7EN from RbConfig and turn off the unit. Restart the SE7EN and try updating again. A number of attempts may be required before the update is successful.

When I start my SE7EN I get a error message during pre-dive test 24, 25, 26 or 27. What can I do?

These faults indicate problems with one of the solenoids due to moisture/water in the pneumatic block. Unfortunately, there is nothing you can do about this error, your e-module needs to be sent to us for repair.


How often do I need to service my Poseidon regulator?

It depends on how much you dive. If you dive 40 - 50 dives a year, we recommend that you service your regulator once every 24 months. If you dive more than that, you should service it once every year. Those that dive every day, should have it serviced at least once every 6 months or so.

Remember that your regulator is life support equipment, designed to keep you alive. If you don't maintain your regulator, it could cause a failure of the equipment.

I have noticed a loud whistling noise coming from the 1st stage on my Xstream regulator, when breathing in it. What is causing this and is it dangerous?

A whistling noise can sometimes be heard when the Xstream first stage is pressurized or depressurized. This is due to a resonance frequency which takes place between the ball bearing and the actuating pin. This noise should however not be detectable during low flow rates such as while breathing. The noise has absolutely no effect on the regulator functionality.

Does my Xstreme regulator have an over-pressure valve in the first stage?

Xstream first stages that has a serial number that starts with 9NNNNN or higher i.e 10NNNNN have a built in over-pressure valve. Built in OPV in Xstream first stages was introduced in 2009.

Can I put a standard Jetstream 2nd stage on an Atmosphere FFM?

The Jetstream PP (the Atmosphere´s 2nd stage) is a modified Jetstream 2nd stage which is constructed to work in conjunction with over-pressure and hold low CO2 levels inside the face mask.

Thus you can NOT put a standard Jetstream 2nd stage on an Atmosphere FFM. Doing that can cause injury or death.

My Atmosphere FFM is vibrating when I breath through it. How can I resolve this?

Most likely, you have your FFM connected to a non-Xstream first stage or the intermediate pressure on your first stage is not correct for the Atmosphere FFM.

What first stages can I use the Atmosphere Full Face Mask with?

The Atmosphere FFM is CE approved together with the Xstream first stage and it's with this first stage the mask performs best. If you intend to use the Atmosphere FFM with another first stage, make sure that the correct intermediate pressure is used.

What´s the intermediate pressure on Poseidon regulators?

The Jetstream and Xstream regulators should be set to 8.5 bar (123 psi) intermediate pressure, at full tank pressure.

The Cyklon 5000 regulator works at an intermediate pressure of 11,5 bar (166 psi) at 20 bar (290 psi) tank pressure.

What Poseidon second stages can I combine with what Poseidon Octopus?

You can mix Jetstream and Xstream 2nd stages/octopus on the same 1st stage, as these two 2nd stages work with the same intermediate pressure. You can NOT mix a Jetstream or Xstream 2nd stage with a Cyklon 2nd stage/octopus. The reason is that the Cyklon 2nd stage works on a higher intermediate pressure than the Jetstream and Xstream 2nd stages. Mixing Jetstream/Xstream 2nd stages with a Cyklon 2nd stage can be dangerous!

Can I use a Xstream, Cyklon or Jetstream regulator with nitrox?

Xstream Deep, Cyklon X and Jetstream Mk3 manufactured after 2015-01-01 are all Nitrox ready from the factory and can be dived with using a maximum of EAN 40. Older Xstream Deep, Cyklon 5000 and Jetstream are not Nitrox ready and can only dived with gas containing a max of 21% oxygen. 

Can I use a standard 9/16 LP hose on my Poseidon regulator?

If the 1st stage you have, has an over pressure valve built in to it, or has an external over pressure valve attached to a LP port, you can use a standard 9/16 LP hose, if it fits on the 2nd stage connection. For the Jetstream and Xstream 2nd stages, there is an adaptor available, that allows you to connect a standard 9/16 LP hose to the 2nd stage.

If I put a Cyklon second stage on a Triton first stage, do I need to modify the Triton first stage in any way?

The simple answer is no. All you need to do, is to adjust the first stage to the correct intermediate pressure that the second stage works at.

Why won´t a LP hose fit in the LP port of my old Cyklon first stage?

On older Cyklon 1first stages, the standard thread size of all ports were 1/8. Today, all LP ports are 3/8 and all HP ports are 7/16 sized.

If you have an older style 1first stage, there are adaptors that can be used, so you can attach standard sized hoses to your first stage.

Male 1/8 --> female 3/8 thread (Article number 2415)

Male 1/8 --> female 7/16 thread (Article number 2910)


Can I attach weight pocket to my One Wing?

Weight Pocket 0355-066, comes with inner pocket and quick release. It can be bolted to the harness via the 40CC system or threaded on any 50mm webbing.

How much weight can I put in the weight pockets of the Origo BCD?

The pockets are normal standard size, which allow you to put 3-4kg or 6-8 pounds on each side.

What is the maximum tank size I can use with the One Wing?

On the inside of the outer wing bladder, there is an inlay, that shows the maximum size tanks that can be used with the W50 and W100 wings.

How do I attach the Besea steel back plate to the harness?

The Besea steel plate replaces the plastic plate that comes as standard with the Besea harness.Use the same bolts, nuts and holes to attach the steel plate.


Why wont my M28 charge?

The M28 needs a charger with a 5.1 Volt / 1A output. A USB port on a computer is sometimes not enough. Try a different charger.

My M28 has a fixed red light. What to do?

You need to update the PMIC. Follow the below steps:

  • Connect the M28 to a PC or Mac with the charging cable
  • Start RbConfig and make sure RbConfig and the M28 has CAN connection
  • Select "CAN" -> "Forced Firmware - M28

The M28 will update and re-boot. If not, contact us.

My M28 flash green (2 times) and red (3 times). What to do?

The problem can be caused by defective buttons that forces the M28 to re-boot. Follow the below steps to troubleshoot:

  • Charge the M28 and make sure it has enough State of Charge to be able to start.
  • Remove one button at a time and try to start the computer

If your computer starts with one or two buttons removed you need to replace the button(s) with new. If your computer still dosn't start, your computer needs to be shipped to us for service.

My M28 has a continuously green flash. What to do?

Something is wrong with the electronics inside the M28. Your computer needs to be shipped to us for service.

My M28 LED light is black. What to do?

If the LED light stays black and dosn't flash in green or red try a different charger. The output must be 5.1 Volt / 1A. If changing the charger dosn't help your computer needs to be shipped to us for service.

gear & Wear

Where can I find the size guides of your products?

Check out the manual section here.


How long is the warranty period on a new Poseidon product?

Most of our products come with a two (2) year factory warranty from the date the product was purchased new. The warranty covers defects due to material and / or production defects. Defects caused by wear and / or improper use are not covered by our warranty.

How do I claim a Poseidon product I have purchased?

In the first instance, you turn to the store where you bought the product. Alternatively, contact Poseidon's representative in the market where you purchased the product.

I've heard that there's a lifetime warranty on Poseidon's products, right?

No, this is a myth that has lived its own life for many years. However, we can still supply many of our older regulator models with service kits and to some extent also spare parts.

I have a support question regarding a Poseidon product. How do I get an answer to my question?

In the first instance, we recommend that you contact our representative in the country you are in. To find contact information for our representatives around the world, visit the following website: insert URL to the correct page. The next option is to send an email to

When I contact what information do you need to handle my question?

The simple answer is that we want as much information as possible. In detail, this is the type of information we want:

  • Which product relates to the question
  • What serial number does the product have, if it is a specific "individual"
  • If there is an error message, preferably as accurately as possible
  • Picture and film on the product help us to identify the product and also any errors
  • Which country you are in is in
  • Log files (if any)


The product I ordered in your webshop don't fit. How do I switch to another size?

Return the product to:

Poseidon Diving Systems AB

Åkeredsvägen 1

421 63 Västra Frölunda


Send with a copy of the delivery note and write on it what size you want instead.

I have placed an order in the webshop but haven't received any e-mail notification. What should I do?
Start by looking in the inbox for spam in your email program. If there is no notification there, send an email to and provide as much information about your order as you can. We will return with information / status regarding your order as soon as possible.

Which countries do you deliver to?

We ship worldwide and have a solid network of distributors and retailers around the world.

I can't find my country in the menu, can I still buy?

We ship worldwide. Send us and email to and we will help out. 

Out of stock?

In the event we run out of stock your local dealer can still hold inventory of the requested item. Check the dealer locator here or sign up for a notification on when we have the item back in stock.