Bleach Dosing?

[Euphylliaphyle]

I will say that in the world of undergraduate bio and chem labs, it's often suggested that one 'drop' from an eye dropper of an aqueous (water based) solution is approximately 1 mL.

A "drop" is usually considered to be between 0.03 and 0.05 ml.
I am not expert, but I count drops every morning when I dose my tank, and this pans out ime. I'd say 0.04 to 0.05 ml per drop, depending on pipette. I use 0.05 to be conservative.
Now back to our regularly scheduled programming...

 

[KrisReef]

IMO- People who put bleach in their tanks, must have dropped something that made them think the idea was a good one?

 

[Fish Fan]

A "drop" is usually considered to be between 0.03 and 0.05 ml.
I am not expert, but I count drops every morning when I dose my tank, and this pans out ime. I'd say 0.04 to 0.05 ml per drop, depending on pipette. I use 0.05 to be conservative.
Now back to our regularly scheduled programming...

When I studied bio and chem in college, we would consider one drop from a regular eye dropper to equal approximately 1 mL. Maybe different droppers would yield different amounts? I guess that would be important to know if one wants to try dosing bleach

 

[Randy Holmes-Farley Verified Community Expert]

Functionally, do you think there is a meaningful difference between dosing ozone, hydrogen peroxide, and bleach? They are all oxidizers, just delivered through different methods.

Ozone has always been attractive to me because it produces crystal-clear, odor-free water and can eliminate stubborn slimes from the sand. I have never measured it, but it also seems like the glass does not need to be cleaned nearly as often. Most of these benefits can often be achieved by running ozone for only an hour or two in the middle of the night.

The downside is that if ozone is destroying odors, color pigments, slimes, and possibly algae, it seems reasonable to assume it is also having some effect on the fish and corals.

Elliot from Marine Collectors was a big fan of ozone until he noticed that small aggression-related nips on fins healed more slowly. They still healed, just not as quickly, which suggested the ozone was affecting the fish. He was also only running it for a few hours each night.

I have often wondered whether hydrogen peroxide might be a better oxidation solution. With ozone, it is nearly impossible to know or precisely control the actual dose reaching the aquarium. That means I never really know whether I am using too much and the uncontrolled dose is material risk to the animals. Hydrogen peroxide, on the other hand, is much easier to dose accurately and consistently. There might be a dose where you get the most benefits with the least risk.

In the end, I always reach the same conclusion: the unknowns make the juice not worth the squeeze. I can achieve most of the same benefits with activated carbon, a healthy biome, and good maintenance practices.

Yes, there are functional differences.

1. Hydrogen peroxide can act as a reducing agent, and is known to reduce copper (cu++) ions in seawater. The other two do not. This highlights one type of difference: what exactly is oxidized.

2. Ozone treatments are often contained and passed over GAC. Bleach could be too, but is it? It is not hard to pass ozone treated water over GAC (I always did) and remove all of the oxidizing species.

3. Hydrogen peroxide is not a very strong oxidant and may not oxidize as many types of organics.

 

[Fish Fan]

not to derail the thread but isn’t the standard pharmaceutical measurement actually 20 drops per mL for water (or 0.05mL per drop)? I have some 2mL syringes and a 1mL autopipette and it seems like 1mL is a lot more than about any “1 drop” i’ve ever seen…

I guess I'm not sure. I always remembered them telling us a drop from a standard eye dropper was about 1 mL, but it was some years ago, so maybe I'm not remembering correctly

I mean, I was wrong once before back around 1986, I supposed it could have happened a second time

 

[FranklinDattein]

I stumbled upon this video the other day and thought it would add to the conversation.

 

[carri10]

Yes, there are functional differences.

1. Hydrogen peroxide can act as a reducing agent, and is known to reduce copper (cu++) ions in seawater. The other two do not. This highlights one type of difference: what exactly is oxidized.

2. Ozone treatments are often contained and passed over GAC. Bleach could be too, but is it? It is not hard to pass ozone treated water over GAC (I always did) and remove all of the oxidizing species.

3. Hydrogen peroxide is not a very strong oxidant and may not oxidize as many types of organics.

To add to this, Ryan, there are two things we are talking about here - how powerful is the oxidiser, which affects how many different types of molecules it can oxidise. There is also what is left behind once the oxidiser has done its job. With bleach, the chlorine has to end up somewhere. With peroxide, the "left over" is water. There is also the speed the oxidiser can work (kinetics), but there my knowledge dries up completely...

 

[Randy Holmes-Farley Verified Community Expert]

FWIW, drop size is controlled by several things, including the liquid density and surface tension, and eapecuially the drip tip size, shape and material (it’s surface free energy).

Some syringes have very thin plastic tips to encourage smaller drops.

 

[Euphylliaphyle]

Some syringes have very thin plastic tips to encourage smaller drops.

Salifert Alk, Mg and Ca kits (perhaps others) use such tips. I should have been more clear, but the drops I was referring to with 0.04 to 0.05-ish ml per drop were from using cheap blow-molded (PE?) pipettes or glass dropper bottles dispensing water (either salt or RO/DI) or AFR or trace element aqueous solutions. My point is that typical "drops" are not 1 ml. Well, maybe using maple syrup and a turkey baster, but most don't think of those situations when talking about "drops" in reefkeeping.

 

[EnterName]

it's often suggested that one 'drop' from an eye dropper of an aqueous (water based) solution is approximately 1 mL.

not to derail the thread but isn’t the standard pharmaceutical measurement actually 20 drops per mL for water (or 0.05mL per drop)? I have some 2mL syringes and a 1mL autopipette and it seems like 1mL is a lot more than about any “1 drop” i’ve ever seen…

Edit: it was already answered, don't know why the app didn't show the responses for me. Just ignore this post

 

[Randy Holmes-Farley Verified Community Expert]

Salifert Alk, Mg and Ca kits (perhaps others) use such tips. I should have been more clear, but the drops I was referring to with 0.04 to 0.05-ish ml per drop were from using cheap blow-molded (PE?) pipettes or glass dropper bottles dispensing water (either salt or RO/DI) or AFR or trace element aqueous solutions. My point is that typical "drops" are not 1 ml. Well, maybe using maple syrup and a turkey baster, but most don't think of those situations when talking about "drops" in reefkeeping.

I agree drops are usually smaller than 1 mL. Drops can be only a few microliters.

In graduate school, my research was on the relationship between surface chemistry and physical properties. One of the main properties I studied was wetting (the tendency for a drop of liquid to bead up or spread out on a surface).

In the course of that work I carefully put many thousands of small drops of water onto surfaces that I prepared. Using something called a contact angle goniometer, I manually placed a drop with a volume of only a few microliters, and measured what it did:

https://www.nanoscience.com/techniques/tensiometry/contact-angle-measurements-and-wettability/

 

[KrisReef]

I agree drops are usually smaller than 1 mL. Drops can be only a few microliters.

In graduate school, my research was on the relationship between surface chemistry and physical properties. One of the main properties I studied was wetting (the tendency for a drop of liquid to bead up or spread out on a surface).

In the course of that work I carefully put many thousands of small drops of water onto surfaces that I prepared. Using something called a contact angle goniometer, I manually placed a drop with a volume of only a few microliters, and measured what it did:

https://www.nanoscience.com/techniques/tensiometry/contact-angle-measurements-and-wettability/

Now I remember why I was chemophobic, too many angles to remember in my distracted nanocephalic capsule.

 

[Ryan - Serious Reefs]

Yes, there are functional differences.

1. Hydrogen peroxide can act as a reducing agent, and is known to reduce copper (cu++) ions in seawater. The other two do not. This highlights one type of difference: what exactly is oxidized.

2. Ozone treatments are often contained and passed over GAC. Bleach could be too, but is it? It is not hard to pass ozone treated water over GAC (I always did) and remove all of the oxidizing species.

3. Hydrogen peroxide is not a very strong oxidant and may not oxidize as many types of organics.

Thanks, that’s helpful.

On the GAC, the problem I’ve run into is that it seems to remove ozone from the top of reactors and skimmers well until the moist air leaving the reactor eventually wets the carbon. Once the GAC becomes damp, it appears to stop removing ozone effectively, and we could clearly smell ozone in the room.

That experience made me wonder how effectively fully submerged carbon is actually removing ozone from water, or at least whether it is as effective as many of us assume. I won’t claim that was the correct conclusion, but after seeing the same behavior repeatedly, I basically assumed that wet or submerged GAC was much less effective at destroying ozone and eventually stopped using GAC on the water effluent.

 

[Randy Holmes-Farley Verified Community Expert]

I used a lot of GAC when using ozone, but I did not see breakthrough of smell in the air or oxidants in the water effluent.

Here’s from the results in my ozone testing:

https://web.archive.org/web/20260108101711/https://reefkeeping.com/issues/2006-05/rhf/index.php#12

Activated Carbon Treatment

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It is important to treat both the air and the water exiting an ozone reactor before they are released into the aquarium and into the room's air. In most of the experiments that I ran, I used a homemade GAC (granular activated carbon) column that treated both the air and water at the same time. This treatment is accomplished, as detailed previously, by inserting the tubing carrying the ozonated air and water mixture a few inches below the surface of an ~20" vertical column of GAC. The water passes down the column and into the sump, and the air can escape by traveling up or down the column through the GAC. When using the Coralife ozone reactor, there are actually two tubes carrying effluent, one carrying water and one carrying both water and air. These were both treated as above.

The effectiveness of this carbon column for treating the air is easy to establish qualitatively by odor. In normal operation, no odor is detectable in the basement room where my sump and aquarium equipment reside. A faint odor of ozone can be detected by smelling directly at the surface of the carbon column, but not otherwise. In my opinion, this level of treatment provided an adequate reduction in ozone levels to be acceptably safe.

However, if the tubing carrying the ozone reactor's effluent is pulled up so that the water flows into the column but the air simply escapes into the room, the entire basement smells strongly of ozone. Consequently, during normal operation the GAC is having the desired effect of catalytically breaking down the gas phase ozone before it has an opportunity to escape.

In order to assess the GAC's impact on the water, the water can be tested for ozone and ozone byproducts (OPO's) before and after the GAC. Using my tubing reactor, with a water flow rate of about 0.5 gallons per minute, I found that the residual oxidant was 0.10 - 0.24 ppm chlorine equivalents before the activated carbon. After the activated carbon, the effluent had an oxidant level of 0.04 ppm chlorine equivalents or less.

When using the Coralife ozone reactor as the reaction chamber, the water flow rate was set to 0.44 gallons per minute, with an additional 0.05 gallons per minute of water in the air/water overflow. Both of these water streams were tested. I found 0.5 ppm chlorine equivalents in the air/water stream and 0.02 to 0.04 ppm chlorine equivalents in the primary water flow before the GAC. The combined flow therefore would have a level of about 0.09 ppm chlorine equivalents. After the activated carbon, no oxidant could be detected (<0.02 ppm chlorine equivalents).

Clearly, the GAC is doing a good job of reducing the highly oxidizing species present in the water. In some tests it was not perfect, but I believe that these levels (< 0.04 ppm chlorine equivalents) are acceptable. Interestingly, the GAC does not greatly lower the ORP. The ORP before the activated carbon was 680 mV after 5-15 hours of equilibration, and was 670 mV after 8 hours of equilibration in the post activated carbon effluent. Consequently, the effluent's ORP is not a suitable way to measure whether the activated carbon is effectively removing residual ozone and its byproducts.