Bob replies...

Hi Brian,

Thanks for the nice words and enjoy the hobby and speaking with fellow hobbyists. And in my retirement years wish to construct the best marine aquarist website possible, one with no product hype or sales pitches!

As for your questions, there's no good reason to maintain pH above that found in the wild, which is 8.0 - 8.2. And, when a calcium reactor is in use, a pH of 7.9 - 8.1 would adequately suffice, since the pH of the effluent from the reactor is generally quite low and somewhat affecting overall pH in the aquarium. Since you don't mention actual pH or the goal of the system, I'm hesitant to go further about this subject, but you might want to read my booklet on water quality where the subject is covered in detail.

As for ozone, a normal molecule of oxygen (O2) has two atoms, and ozone (O3) has one additional atom. The extra atom is highly unstable and is an intense oxidizing agent. The main reason for its use is to eliminate unwanted dissolved organic products by increasing the systems REDOX/ORP. Redox means "reduction/oxidation" and applies to a sequence of chemical events in which elements and compounds transfer and/or rearrange positive and negative electrons. Elements and compounds that want to gain an electron are called "reduction agents" and have a negative charge. Those that want to give up an electron are called "oxidizing agents" and have a positive charge. We measure the effectiveness of this process by the minute electrical charge it generates in millivolts (mV) with an Oxidation Reduction Potential (ORP) meter.

Another way to look at it is that it's like resistance in electrical wiring. The more resistance the less electric current flow. The dirtier the water, the less ability/potential it has to conduct electricity. That is real basic, but I hope you get the point. High quality ocean water, e.g., around outer coral reefs, has an ORP of 350 to 400 mV. Most of the corals we keep in our aquariums come from lagoon areas where ORP is 200 to 300 mV. So a reading of 300 - 400 would be acceptable for most systems, however, other aspects would have to be considered. That would include the systems goals and an actual ORP reading.

The equipment needed consists of a device to generate the ozone (ozonizer), a gauge and probe to read aquarium's ORP, and a controller that can set the desired level by turning on/off the ozonizer. Bear in mind the effluent from an ozone contact chamber (preferably a protein skimmer) must be passed over a bed of activated carbon to remove residual ozone before it returns the aquarium. Even though residual ozone is fairly short lived, usually less than an hour, the residual can damage fish tissue and invertebrate.

And ozone does not add dissolved oxygen to the water, at least in any significant quantities that would benefit any of the aquariums' inhabitants. Nor does it have anything to do with carbon dioxide. Depending upon your goals and maintenance practices, it is very possible to get by without it. Before turning to its use, increase dissolved oxygen in the aquarium by increasing water circulation, reducing bio-load, trying a more efficient skimmer, removing any aquarium covers, and/or increasing the general level of maintenance. If you're already doing these things, then find out what the actual ORP reading is in your aquarium, then contact me and we will go from there.

Hope this helps,

Bob