A: Much of the Nitrox Stik is made out of PVC.  PVC is durable, does not corrode, and fabricates easily.  This means the Stik will last forever and is essentially maintenance free.  But there is more to the Nitrox Stik than it's attractively painted PVC exterior, and beautiful laminated mounting board.  A stainless steal air filter and helical mixing vanes are the heart of the Stik's function and performance.  Considerable engineering, analysis, testing and expense have gone into developing a system that thoroughly mixes the gases while causing very little restriction on the air compressor.  If you attempt to manufacture something yourself that either insufficiently mixes the gases or causes too much restriction, you will dramatically reduce the life of your air compressor.  Additionally if you make something like the Nitrox Stik yourself, you are assuming sole responsibility and liability for its performance, if something goes wrong, its all your fault.  After you fry the inside of your air compressor and it costs you thousands to either replace or repair, you'll say to yourself, "Self, it would have been a heck of a lot less expensive and much less headache, if I had only purchased the Nitrox Stik to begin with."  So in the immortal words of Dirty Harry, "Do you feel lucky, well, do you, Punk?"

A: Sort of.  The concept of Nitrox Continuous Gas Blending was originally conceived by Dr. Morgan Wells who worked for the National Oceanic and Atmospheric Administration (NOAA).  He patented the concept but didn't have a practical design until Mr. Ross Cowell, a marine engineer, came along and developed the Nitrox Stik you see today.  Mr. Cowell patented the Nitrox Stik in the USA and Canada and receives royalties for the sale of every Nitrox Stik.  There are several knock off "Sticks" that are infringing on this patent and being illegally imported and sold in North America.  Envirodive Services, makers of the Nitrox Stik, is presently taking legal action to stop the sale and distribution of these illegal imports.

A:  The Nitrox Controller has a number of features that make the operation of the Nitrox Stik easier.  The controller measures the concentration of oxygen at the outlet of the Nitrox Stik and either incrementally opens or closes the oxygen supply valve to achieve the desired Nitrox mix.  The computer in the controller is vastly superior at this sometimes tedious task than any human could be.  This frees up the operator to attend to other matters in the Dive Shop while filling Nitrox: helping customers; answering phones; running the register, etc.  The Nitrox Controller also has safety features that shut the oxygen supply valve and alert the operator if there is a problem.  It really boils down to time and what your time is worth.  To be a safety conscious operator, you need to monitor the process of filling Nitrox.  If you determine the cost of labor associated with filling Nitrox there is a strong financial argument for purchasing the Controller.  The Controller could save you thousands of dollars in labor costs over its life.

A: You should consider buying a Nitrox Controller.  The controller can be purchased with custom wire lengths that will allow you to position the controller wherever would be most convenient for you.  This way you can monitor the process of making Nitrox without feeling like a leper.  The Nitrox Controller would also allow you to be productive in the shop while you are filling Nitrox.  There are a number of dive shops that already use the controller this way.

A:  That really depends on how much Nitrox you are filling.  There are a couple of things you need to look at: initial system costs and reoccurring costs, including the price of oxygen, electricity, labor, and supplies.  Follow this link to an Excel spreadsheet that will compare the various costs associated with making Nitrox.  Edit the assumptions to reflect the costs (labor, #  of Nitrox fills per month, Compressor costs per SCUBA tank fill, etc.) associated with your dive shop to see which method is most cost effective for you.

Nitrox Cost Breakdown Spreadhseet

Here is another spreadsheet to help you understand the costs of filling a SCUBA tank at your shop.  Edit the fields highlighted in yellow to reflect the costs associated with your compressor and shop.

Tank Fill Cost Spreadsheet

A:  The Nitrox Stik requires very little maintenance.  The blender unit has a stainless steel filter that needs to be periodically cleaned.  You simply remove the oxygen hose from the barbed fitting, unscrew the filter from the blender unit, pull off the wind diverter, and wash the filter in warm, soapy water.  You won't need the the paper/foam pre-filter on your compressor any more as the Nitrox Stik's high quality stainless steel filter serves this purpose.