Mares Abyss Octo, brand new, not breathing well

If free flow from the moment the unit is pressurized it could be the 1st stage intermediate pressure (IP) is too high or the second stage valve seat is missing, set screw is too loose, seat is damaged or has debris on it. If the free flow gradually increases under pressure it usually indicates a damaged 1st stage valve seat. A trained Mares Tech with the correct tools and genuine parts would be the best solution.

It may be that you have picked up a little bit of sand or grit, give it a good vigorous wash in the bath. Often octo's get dragged along the bottom and get rubbish in them. If it does need adjusting I strongly recommend you get a professional to do it. :)

Yes. Especially if the regulator is well tuned. If you turn it over slowly, letting the 2nd fill with water without blasting air, it should NOT leak. If it does under those circumstances or when held mouthpiece down, it needs to be serviced.

A well tuned reg will easily freeflow. Try holding the mouthpiece downward and SLOWLY rotating to fill the 2nd stage with water.
If that does not stop the freeflow and/or if the 2nd bubbles even with the mouthpiece held downward, the you need to get the reg serviced.

Friend, if you can't figure out how to open "it" (are you referring to the 1st or 2nd stage?) do you think you are capable of repairing a piece of life support equipment?

Freeflow can be caused by several things, most of which require new replacement parts, special tools and instruments and knowhow.

Please, think again, don't mess with life critical stuff you don't understand, and live a longer life.

Hi. I would suggest having the internal o-rings checked. One of them could be worn, allowing the air to escape. Or put it into your local dive shop for a service.

Pressure inside 2nd stage should be the same as ambient so no water should enter. Maybe should adjust to freeflow and then a nough
back until free flow just stop. careful your reg will now be very sensitive.
Another problem could be a worn exhaust valve - change a new one, see if it helps.
Good luck,
Eddie Foo (Malaysia)

An octo IS a regulator. There are two types or regulators on a typical scuba rig. Your first stage reg that is attached to your tank valve. From this first stage, there are hoses leading to your primary breathing second stage reg and your Octo second stage. The job of the first stage is to bring that possibly 3,000 psi air in the tank, down to a more reasonable pressure of about 150 psi. From there, the air goes to the second stages and can be reduced down further by these second stage, on demand (meaning it delivers air when you inhale and stops when you finnish inhaling), regs. The Octo is a second stage back up for a buddy that is out of air or if your own primary second stage ( the one you normally breathe from) is no longer functioning. Octos are generally ( not always) a cheaper reg, that may not have all the bells and whistles that a primary air source does. It's there for an emergency, so ease of breathing under load and tuning adjustments are minor. It gives you air when you're in a pinch, thats the important thing.

The scuba regulator is employed in an open-circuit scuba set. Said scuba equipment reduces high air pressure conveyed by the diving cylinder to the first stage and feeds breathable gas to the diver through the second stage's mouthpiece. Also called pressure regulator or demand regulator, the scuba equipment is one of the essentials to diving that determines breathing quality and inhalation effort during the dive. But given the different types of regulators and the pertinent design of its first and second stage components, how should a neophyte diver - or even a seasoned diver at that, choose a scuba regulator that incorporates user adjustment and delivers a venturi-assisted air flow in its features? Consider your diving purpose and frequency. Better yet, take note of the following criteria to guide you in your purchase: 1. The Scuba Regulator's Mouthpiece. Check the specifications if the regulator is outfitted with a patented orthodontic mouthpiece. This implies that it is ergonomically-designed to accommodate an overbite or underbite by the human mouth. An ergonomic mouthpiece helps reduce fatigue in the mouth and jaw area, particularly in the cruise of lower depths and extended dives. 2. User Adjustment Settings. There are optimally-designed scuba regulators that are outfitted with adjustment levers to therefore allow divers to finetune valve settings in order to provide the least possible inhalation effort throughout the dive. One notable scuba equipment is the Aeris AT 400 Pro Regulator that is equipped with an adjustable second stage. 3. Weight of the Scuba Regulator. Visualize yourself on a dive and using just any other type of scuba regulator. Is the regulator bulky to considerably increase drag and cause jaw fatigue or is it buoyant enough for you to carry around with your mouth? Lightweight scuba regulators use polycarbonate thermoplastics for its housing to make the scuba equipment compact, sturdy and corrosion-resistant that makes them fit for extended use. 4. Nitrox Compatibility. This entails an ocular inspection of the cylinder tank (Nitrogen and Oxygen proportions) and scuba regulator (Nitrox compatibility) specifications. As a matter of convention, most regulators are suited for nitrox mixture use out of the box; containing the standard, maximum proportion of 40% Oxygen (in terms of volume) but then again, there are gas mixes supporting leaner proportions of oxygen such as the trimix. Therefore, check if the scuba regulator supports the gas mixture configured for your diving cylinder prior to purchase. 5. No-Contaminant Feature. As much as possible, choose a diving regulator that has been manufactured using Dry Valve Technology (DVT). DVT operates through an automatic valve that prevents contamination of the first stage mechanism to thus prevent regulator flooding and the entry of moisture or dust particles. This likely improves scuba regulator performance and extends its useful life. 6. Air-Sharing Feature. This feature often associated with octopus regulators (used as a spare demand valve or alternate second stage) will prove to be most helpful during diving emergencies such as a free flow or during diver rescues. High performance octopus regulators such as the Aeris Gyro Octopus Regulator are designed lightweight and with air-sharing feature, while sporting an inline swivel for convenience mounting and flexibility

"The second stage regulator takes the manageable pressure coming from the 1st stage through the hose and delivers it to your mouthpiece in a way that is comfortable to breathe. Where the 1st stage is only concerned with letting air flow into the hose the 2nd stage has more complex machinery which handles both inhaling and exhaling through the same mouthpiece. Like the first stage the 2nd stage scuba regulator uses a diaphragm or piston to open a valve. Breathing in from the mouthpiece reduces the air pressure inside the chamber, water pressure pushes the diaphragm in, which opens the intake valve. When you stop inhaling the pressure in the chamber balances and the valve closes. The result is an air delivery system which supplies air only when you are inhaling and does not leak air constantly through the mouthpiece. A well balanced and well-maintained scuba regulator does its job so well that breathing feels natural and effortless despite the all mechanics involved. The second stage scuba regulator also has a purge or exhaust valve, which lets your exhaled air out of the chamber, but doesn't let water in. When you exhale into the second stage scuba regulator the pressure inside the chamber becomes greater than the ambient pressure. The exhaust valve is a simple one-way valve which lets this air escape. The second stage scuba regulator also has a purge or exhaust valve, which lets your exhaled air out of the chamber, but doesn't let water in. When you exhale into the second stage scuba regulator the pressure inside the chamber becomes greater than the ambient pressure. The exhaust valve is a simple one-way valve which lets this air escape. A second stage scuba regulator also has an ""emergency"" or ""purge"" button which forces the intake valve to open. When the purge button is pressed air will flow continuously into the chamber and escape either through the mouthpiece or the aforementioned exhaust valve"