A lot of people seem to have questions about various electrolytes used in the production of HHO. I thought it would be a good idea to create some sort of resource to help people understand the various choices out there. Maybe a moderator can make this sticky or something.

Tap water:
Contains god knows what in the way of additives. This will vary from place to place. Does it work? Yes. But you will have varying results if you need to fill up in a different county. In most places tap water contains Chlorine as a biological inhibitor. During the electrolysis process this will create chlorine gas along with the HHO. For anybody with Aluminum parts in your engine this could spell disaster. It has been suggested that you should let the tap water sit in a open jar for 48 hours with a piece of cheese cloth over the top to keep out the dust. This will allow the Chlorine to dissipate out of solution, kind of like what some people do when they first fill a fish tank to protect the fish.

Distilled water:
This is by far the most suggested for use as a base. Distilled water by itself doesn’t conduct electricity very well. This means that you will need to add some sort of electrolyte to the mix. If you are trying to be somewhat scientific about your experimentation then this is what you want.

HVAC condensation:
This has the advantage of being very cost effective as you are already using the AC to keep cool. All you have to do is collect the condensation for use later. It is distilled water in the general since, but since it isn’t in a controlled environment it may contain impurities. But hey, it doesn’t cost any more than the standard use of your AC.

Sea Water:
Sea water of course contains NaCl or salt. This will be extremely corrosive on your plates. Could also be real bad if you get any in your engine. There are several thoughts on how this breaks down chemically during the electrolysis process and will produce poisonous gases. There was someone who talked about boiling the sea water until the NaCl fell out of solution and then use what is left. It has potential, but be prepared to replace major components of your cell on a regular basis.

Hydrogen Peroxide:
Or H2O2. The stuff you buy off the shelf is only 3% by volume. The rest is just H2O. Hydrogen peroxide breaks down very easily with light or heat. As such it doesn’t do much for you in the long run. It is mildly acidic, but it turns to water in a very short time once the cell starts to heat up.

Vinegar:
Vinegar has a real low boiling point and thus tends to be a poor choice as an electrolyte. What happens is the cell starts to boil and you loose most of your electrolyte to evaporation. However it works real well as a cleaning solution for your cell. If you want to get rid of the junk left over from Sodium bicarbonate or finger prints on the plates… etc… Some even use it to pre-condition there cells for a better production rate with other electrolytes.

Table salt:
Or NaCl. Creates Chlorine gas during electrolisys. Extremely corrosive. Does it work? Yes, but probably not the best choice.

Epsom Salt:
Also known as Magnesium Sulfate or MgSO4. Does it work? Yes, but what are you creating in the process? Any Chemist out there want to speculate? My high school chemistry sugest that you could end up with MgO + H2S04. Magnesium Oxide and Sulfuric acid. Again I am not a chemist, so I avoided testing with this.

Sodium Bicarbonate:
Also known as Baking Soda or NaHCO3. This is probably the one that most people start out with as they have it in their kitchen. It does work, but there are better results with NaOH and KOH. It is believed that sodium bicarbonate will break down to NaOH and CO2 gas in the electrolysis process. Also it creates a brown colored gunk in the cell and most believe that, over time, will reduce the output of the cell.

Sodium Hydroxide:
Also known as lye, caustic soda or NaOH. Has the advantage of being fairly easy to purchase (usually sold as drain cleaner). Does not get used up in the electrolysis process such that all you have to add is water periodically. Great results. Can burn the skin if you come in contact with it.

Potassium Hydroxide:
Also known as potash or KOH. Considered by most to be the best option. Can be found in specialty shops that make soap. It conducts electricity better than NaOH so less is needed in solution. Like NaOH it can burn the skin if you come in contact with it.

How much electrolyte should I use?
That depends on so many variables it is almost impossible to define. The going answer to this question is this. Start with figureing out what the maximum temperature your cell design can handle. Subtract about 20% for safety from that and call it your max cell temperature. Then heat your distilled water up to that temperature and poor it into the cell. Then add ¼ teaspoon of electrolyte. Hook up your cell to the power source and take an amperage reading. You can then add small quantities of electrolyte to your cell until you get the amperage that you are looking for. This will get you close to the operating ability of your cell design. Example: If you are using CPVC to build you cell, it is good up to about 180 degrees F. So you would heat your water to 140 degrees. The amount of amperage is really dependent on what you think your car can handle. Probably no more than about 20 amps realisticly. If you find that your cell is getting too hot, then just back off of the electrolyte.

What should I do with my used electrolyte?
That depends on what your cell is made of. If you are using any metal that is chrome plated, contains Chrome or Chromium like stainless steel. Then you end up leaching something call Hexavalent Chromium out of the metal during the electrolisys process. Hexavalent Chromium or Cr(VI) is a known carcinogen and is bad juju if it gets in the drinking water (see the movie Erin Brockovich). In this case don’t pour your used electrolyte down the drain. Mark it with the chemical name of the electrolyte { Example NaOH & Cr(VI) } and take it to your local Hazmat collection center.

If your cell is made out of something like Carbon plates, you wont have the above problem. It would probably be safe to just dump it down the drain.