Ozone and Corals

[Rocco8]

Its it necessary to use carbon on the discharge of the protein skimmer when using ozone?

My corals don't look fully open since starting ozone.

I understand that ozone converts bromide ion to hypobromous ion which is toxic. Carbon supposedly reverses this.

Any thoughts on this?

[HighlandReefer]

Ozone and the Reef Aquarium, Part 1: Chemistry and Biochemistry
http://reefkeeping.com/issues/2006-03/rhf/index.php


From this article:

"The Effect of Activated Carbon on Ozone Produced Oxidants

In order to reduce ozone's potential toxicity, aquarists typically try to reduce the OPOs in the effluent coming from the ozone reaction chamber. There are a variety of ways to accomplish that, but by far the most commonly used is passing the water over activated carbon (GAC).

In a previous article on how reverse osmosis/deionizing water purification systems work on tap water, Reverse Osmosis/Deionization Systems to Purify Tap Water for Reef Aquaria, I showed how hypochlorite reacted with activated carbon. Bromate and hypobromite are expected to react similarly. The reactions within the activated carbon that break down these compounds rely on having enough active surface area and time for these catalytic reactions to take place. How effective that is in a high flow application such as a skimmer's effluent is unclear. It is effective in reverse osmosis/deionization (RO/DI) applications because the flow is low and the carbon's surface area is very high.

When bromate and hypobromite interact with the activated carbon's surface, they are broken down into bromide ion (Br-) and oxygen as shown below for bromate, where C* stands for the activated carbon and CO* stands for the activated carbon with an attached oxygen atom.

BrOH + C* à Br- + CO* + H+

Some of the oxidized activated carbon remains, and some breaks down to produce oxygen (O2):

2CO* à 2C* + O2

Some of the CO* can also break down to CO2 (carbon dioxide) in a noncatalytic breakdown of the OPO, but that is typically a small fraction of the total. None of these products of reactions are of significant concern to reef aquarists.

The big question for each aquarist is how effective is the GAC that is being used? As is true for many things examined in this field, the studies often have been done at high OPO concentrations relating to disinfection, and are usually in freshwater. In one patent application, a GAC bed was used to reduce the OPO in the water passing through it from 1.1 ppm to less than 0.2 ppm.66 Another group showed that completely removing the bromate required a contact time with the activated carbon of more than 15 minutes.67 In this test and in many others that have been published, older activated carbon was less effective than new activated carbon. The reason is that organics occupy portions of the GAC's surface where bromate and other OPOs are broken down.

A second group studying bromate in drinking water showed that GAC could remove 78-96% of bromate.68 They found that contact time and age of the carbon were important parameters affecting the removal percentage.

Besides activated carbon, there are other potential ways to remove OPO's. In one patent application, researchers have shown that the water used in aquaculture applications can be treated with ozone, and then with reducing agents that react with and destroy these agents, thereby reducing its toxicity.69 They recommend sulfite, bisulfite, metabisulfite or thiosulfate for that purpose, but it clearly is not simple to accomplish this automatically in a reef aquarium.

Does GAC or any other of these methods work well enough for reef aquarists to use ozone without undesirable side effects? The answer likely depends on the care which is used in the GAC treatment, and the aquarist's tolerance for OPOs to pass into the aquarium. The answer is likely not well enough when using the highest doses typically used by aquarists and the lowest tolerance for OPOs (that is, the lowest levels likely to cause ANY undesirable effects). Because it is not easy for most aquarists to measure low concentrations of OPOs, the most prudent course of action (aside from not using ozone) is to pass the ozonated aquarium water over as much GAC as possible before letting it re-enter the aquarium."

[Rocco8]

I am looking for some novel way to add a container with carbon on the discharge of the protein skimmer outlet pipe. These tend to raise the foam level in the throat of the protein skimmer. The Nozzle on the protein skimmer outlet pipe is 1 1/4" PVC and adjustable. It is an ASM-G1. Any pictures of devices would be appreciated.

Thanks,

[HighlandReefer]

It may be helpful to post this in the Equipment Forum also.

[Rocco8]

Thanks cliff

[HighlandReefer]

Your welcome.

Hopefully others will provide some ideas for you.