the result astonishing me - with ozone!!!

[Bigair]

Actually, ozone was the last thing on my shopping list due to concerns about potential health problems. However, in my battle against high organic matter in the tank, I've exhausted all other methods like Zeo, activated carbon, a large protein skimmer, and UV sterilization, none of which significantly reduced the organic matter concentration in my aquarium.

Until three days ago, when I introduced an ozone generator and used ORP to automatically control its operation, maintaining the ORP within the 360-400 range. Today, I cleaned the green hair algae from the live rocks with a teeth brush, and as some aquarists may know, this can really make the tank water look cloudy! Haha!

Then, I increased the ozone supply, and after three hours, I took a sample of water. In both of the images below, the water on the right side is from this sample. In the first image, the left side is the water from my tank three days ago, which appears yellowish. The contrast is quite evident, isn't it?

What astonished me is the second image. On its left side is the RO water with TDS at zero, and it's not as clear as the water from my tank right after I cleaned it. believe me I used different view angles and light sources, the comparisons have same results.

So, does this mean that even the RO/DI water I painstakingly produced with zero TDS still had residual dissolved substances? And anyway all of these were effectively removed by the ozone generator! It's truly remarkable how powerful ozone can be.

 

[Bigair]

with ozone, tank water could be clearer as tds=0 water!

 

[Randy Holmes-Farley]

Ozone is certainly super effective at reducing yellowing. Many folks say it makes the water nearly disappear.

However, it can be a little deceiving because the chemical reactions it is best at remove the color from many organic compounds without actually removing the organic material itself.

 

[Bigair]

Ozone is certainly super effective at reducing yellowing. Many folks say it makes the water nearly disappear.

However, it can be a little deceiving because the chemical reactions it is best at remove the color from many organic compounds without actually removing the organic material itself.

I'm leaning towards the belief that ozone does indeed effectively remove organics, especially since it's become my last hope. I've come to learn that having a TDS reading of 0 doesn't necessarily mean that organics are undetectable or absent. So, I do believe that achieving a TDS reading of 0 can be somewhat deceptive, potentially serving as a significant source of organic input, which many people use for water top-ups.

 

[Bigair]

If my assumption is correct, how do you address the issue of excess organics in RODI water with a TDS reading of 0? Do you use additional DI units?

 

[Randy Holmes-Farley]

If my assumption is correct, how do you address the issue of excess organics in RODI water with a TDS reading of 0? Do you use additional DI units?

I’m not sure what you are suggesting, but I’m not speculating on the effects of ozone. It is known science. It will decolor traces of organics in ro/di as well, if you think that desirable, but they likely didn’t come through the ro/di but likely came after the water left the unit. And it doesn’t remove the organics, just reduces the color.

Ozone and the Reef Aquarium, Part 1: Chemistry and Biochemistry by Randy Holmes-Farley - Reefkeeping.com

Ozone and the Reef Aquarium, Part 2: Equipment and Safety by Randy Holmes-Farley - Reefkeeping.com

Ozone and the Reef Aquarium, Part 3: Changes in a Reef Aquarium upon Initiating Ozone by Randy Holmes-Farley - Reefkeeping.com

From the first one:

Oxidation of Organics by Ozone: Decoloration

---

The oxidation of organics is, it turns out, the primary reason that reef aquarists use ozone because it is the organic material in seawater that causes clarity and color issues. Its impact on organic materials is also why ozonation impacts skimming. While most organic compounds that are exposed to enough ozone for a long enough period will be oxidized in some way, some are very much more sensitive than others. In fact, at the levels of ozone attained in a typical reef aquarium contact chamber (less than about 0.3 ppm ozone) or even disinfection applications where the doses are much higher, the total dissolved carbon does not appreciably change during the ozone exposure (although it may later if bacteria find the newly oxidized organics more bioavailable; see below).

In a marine mammal pool,18 for example, it was found that disinfection with 4 ppm ozone with a 30 minute contact time (a disinfection level much higher than is typically used in reef aquaria) did not reduce the pool's total organic carbon (TOC) (~13 ppm TOC), while the use of granular activated carbon (GAC) did reduce it by 37%. Interestingly, the combination of ozone and GAC was even more effective, removing 60-78% of the TOC, suggesting that the ozonation may have altered some of the molecules in a way that made them bind more strongly (or more rapidly) to GAC. An alternative explanation that cannot be ruled out involves biological transformations of the organic compounds taking place on the GAC surface as it became colonized with bacteria).

One research group19 studying the reaction between a variety of organic compounds and ozone concluded:

"…comparisons of rate constants with chemical structures of the reacting groups show that all reactions of O3 are highly selective…"

Fortunately, many of the organic compounds that are most reactive with ozone coincidently are those that aquarists want to eliminate from aquaria. As seawater ages in marine aquaria, the water often becomes yellow as a wide variety of different organic pigments build up. Because of the ozone's reaction with many natural pigments, it is often used in drinking water purification for the purpose of "decoloration;" not organic removal per se, but decoloration.20

In order to understand this effect, it is first instructive to understand which organic molecules lead to coloration, because not all of them do. In fact, most organic molecules are not colored. That is, they do not absorb visible light. Looking through bottles of purified organic compounds, the vast majority are white powders. Organisms, however, have a significant need to absorb light, for example, to photosynthesize or to see.

In order to generate molecules that absorb visible light, natural systems often turn to conjugated carbon-carbon double bonds. Figures 1 and 2, for example, show the structures of chlorophyll and b-carotene. Both of these molecules are widespread in organisms, and both contain conjugated double bonds that lead to the absorption of visible light. These figures do not show the hydrogen atoms (there are dozens of them), but all of the other atoms are shown, and there is a carbon at each intersection of two or more lines. This is how chemists often show structures, allowing the important features to stand out and not get lost in a clutter of atomic letters. What is important here is each segment with a C═C (shown in red). Without going into ridiculous chemical detail for a reef article, having a bunch of C═C bonds arranged together with a single C─C bond between them can lead to the absorption of visible light. That is why organisms have developed such chemical structures for the absorption of light despite their instability toward oxidation (see below).

It is just that instability, however, that aquarists take advantage of when employing ozone. Figure 3 shows, for example, where ozone first attacks oleic acid (a dietary fatty acid).21,22 It is attacked at its double bond, breaking it apart into smaller fragments that no longer have a C═C bond. Consequently, while a huge dose of ozone lasting a very long time will break down these bits even more, even a small dose will remove the C═C bond.

Translating that reactivity to the pigments shown in Figures 1 and 2 makes it apparent why ozone is so good at reducing seawater's coloration and increasing its clarity: it reasonably selectively targets many of the structures that nature uses to absorb light, and converts them to nonabsorbing chemical structures.

A second type of colored organic compound that accumulates in seawater (in both the ocean and aquaria) is one of the functional groups in humic and fulvic acids (the compounds often identified as the yellowing agents in aquaria).20 These "compounds" are complex mixtures of many compounds, but among them is the phenol functional group (Figure 4). Phenol can be attacked by ozone,23,26 with breakdown products shown in Figure 4. It is the Ring-OH group that is colored when in the Ring-O- ionized form, and many of these breakdown products lack such a functional group. Hence the oxidation of such phenolates in humic acids with ozone will reduce color in aquarium water.

The various chemical products described in this section are, of course, not the only reaction products of ozone, hypobromous acid and hypobromite with organic compounds. Other products include brominated organic compounds and many other chemical structures. These have not been fully elucidated, a fact which is not surprising since even in the absence of ozone, the nature of all of the organics in natural seawater or reef aquarium water remains poorly defined.

 

[Bigair]

seems I still need to use carbon to really get organic down..

 

[Bigair]

There is indeed a great deal of uncertainty, especially when it comes to distinguishing between color organics and transparent organics. No one seems to have a clear-cut definition for them. From what I've gathered, the lesson might be not to take anything for granted, as the aquarium world is full of mysteries and surprises!

 

[Dan_P]

Actually, ozone was the last thing on my shopping list due to concerns about potential health problems. However, in my battle against high organic matter in the tank, I've exhausted all other methods like Zeo, activated carbon, a large protein skimmer, and UV sterilization, none of which significantly reduced the organic matter concentration in my aquarium.

Until three days ago, when I introduced an ozone generator and used ORP to automatically control its operation, maintaining the ORP within the 360-400 range. Today, I cleaned the green hair algae from the live rocks with a teeth brush, and as some aquarists may know, this can really make the tank water look cloudy! Haha!

Then, I increased the ozone supply, and after three hours, I took a sample of water. In both of the images below, the water on the right side is from this sample. In the first image, the left side is the water from my tank three days ago, which appears yellowish. The contrast is quite evident, isn't it?

What astonished me is the second image. On its left side is the RO water with TDS at zero, and it's not as clear as the water from my tank right after I cleaned it. believe me I used different view angles and light sources, the comparisons have same results.

So, does this mean that even the RO/DI water I painstakingly produced with zero TDS still had residual dissolved substances? And anyway all of these were effectively removed by the ozone generator! It's truly remarkable how powerful ozone can be.

How are you measuring dissolved organic material in the water to known whether it is high or not?

 

[Bigair]

How are you measuring dissolved organic material in the water to known whether it is high or not?

simply viewing via growth of GHA

 

[Dan_P]

simply viewing via growth of GHA

OK, but doesn’t the hobby consider nitrate and ammonia as the growth promoters of algae growth?

 

[Bigair]

OK, but doesn’t the hobby consider nitrate and ammonia as the growth promoters of algae growth?

I have too much GHA, and I now confirmed that TDS zero water is a source of organic

 

[Randy Holmes-Farley]

There is indeed a great deal of uncertainty, especially when it comes to distinguishing between color organics and transparent organics. No one seems to have a clear-cut definition for them. From what I've gathered, the lesson might be not to take anything for granted, as the aquarium world is full of mysteries and surprises!

Again, that is not true. Chemists can easily distinguish colored or non colored organics.

 

[Randy Holmes-Farley]

I have too much GHA, and I now confirmed that TDS zero water is a source of organic

IMO, organics are not a cause of green algae, and the hint of color you saw can easily be from traces of inorganics as well.

 

[Randy Holmes-Farley]

simply viewing via growth of GHA

That's a false assumption.

 

[Bigair]

IMO, organics are not a cause of green algae, and the hint of color you saw can easily be from traces of inorganics as well.

Since I've left most of my chemical knowledge behind in school, I don't intend to argue with you as an expert in this field. However, there are times when I read your articles or posts, and I initially think, "Okay, I've learned a lot, and what you're saying does make sense." But later on, I find myself feeling even more strongly that it's all about uncertainty. It seems like everything can potentially cause anything, and that's the conclusion I've reached. It can be a bit perplexing at times. Personally, I prefer experimenting based on my instincts rather than delving deep into atomic details. In any case, it's been a great conversation.

 

[BZOFIQ]

@Bigair

Do you know what your phosphates & nitrates are at?

 

[PeterErc]

Wow! Glad the ozone is working for you, simply amazing, You could also read about turbidity in RODI water. Sterilizing the permeate with UV could also help if you want sparkling clear RODI.

If it was me I would be glad the ozone is giving me good results and leave it at that.

 

[KStatefan]

I have too much GHA, and I now confirmed that TDS zero water is a source of organic

How was that confirmed?

 

[jimk60]

I have too much GHA, and I now confirmed that TDS zero water is a source of organic

Not really sure you can present anecdotal evidence such as this as conformation