Hydrogen Sulfide and White Film/Mat Questions ...

[jdg]

I have a 250g system, FOWLR at this time, and things have been running fine. In the last several days, I noticed a distinct rotten egg smell coming from the system -- at first I thought it was just my skimmate collector, but I cleaned that out before leaving town for a day. When I returned, I noticed that the rotten egg smell had gotten worse (I'm presuming hydrogen sulfide) and I started to notice a white film (almost looks like frost) starting to accumulate on some of the rocks and in the sump.

I normally dose organic carbon (vodka) and I run a bio-pellet reactor to keep nitrates in check; together, they did a very good job.

I tested for nitrates today and they were off the chart, which made absolutely no sense ... until I found out this evening that several days ago, my son decided to help feed the fish by dumping an entire (and new/full) container of new life spectrum flake food in the sump along with a considerable amount of vinegar (likely exceeding 16oz ... yes ... ounces). It also may have occurred more than once over the last week or so -- I am "investigating".

At this point, my assumptions are that the white mats/film is a bacterial bloom and the smell is hydrogen sulfide produced from said bacteria?

The fish all appear normal at this time, but I know that can change relatively quickly.

My question is: How do I clean this up? I've started with a small water change (10%) so far -- I would have done more but my holding tank was depleted. Nitrates are so high, I will likely have to do a few very large changes I suspect. Should I start removing the white film where I can, or is that going to make things worse?

Should I discontinue vodka dosing?

Will purigen or activated carbon help at all?

Most importantly, I understand that hydrogen sulfide is extremely toxic; the smell is making its way around the entire house and isn't really localized to the tank anymore. How dangerous is this to kids/pets? If it goes on several days, could enough accumulate to become dangerous to them?

Any suggestions/help would be greatly appreciated.

Thanks in advance!

 

[HighlandReefer]

Regarding the smell in the house, I would open windows & doors and place fans to help remove interior air to exterior.

Regarding how to deal with your tank problems, this is what Randy recommends:


Hydrogen Sulfide and the Reef Aquarium
http://reefkeeping.com/issues/2005-12/rhf/index.php


From Randy's article:

"Preventing and Dealing with Hydrogen Sulfide
--------------------------------------------------------------------------------

Aquarists sometimes have to deal with situations where hydrogen sulfide exposure is a possibility. The suggestions below may be useful in preventing or correcting such problems.

1. Avoid burying organic materials under sand or rocks. This organic material decays, and that decay can drive the formation of hydrogen sulfide. Burying live rock under sand, for example, will likely kill many organisms and when they decay, H2S may be formed.

2. When using a denitrator, be careful not to set its flow too slow so that nitrate is eliminated and sulfate reduction takes over. The ORP in the denitrator may or may not be a useful guide here, depending on the setup.

3. Do not store live sand for extended periods without placing it in circulating aerated water.

4. Do not add organisms (such as certain fish) that dig up sand beds if there is significant potential for hydrogen sulfide release.

5. Be careful that equipment failures (such as a powerhead falling off the side of an aquarium onto the sand) will not disturb sand beds if sulfide deposits are suspected.

6. Do not stop the flow of aquarium water inside piping or other closed systems for more than an hour or two. If it is necessary to stop the flow for a longer time, collect the water rather than sending it back into the tank.

7. Do not store tank water or natural seawater without stirring and aeration for more than a few hours. Raw artificial seawater made with pure fresh water does not have this concern, as there are no organics in it to decay. It can be stored unstirred for as long as desired.

8. If an anoxic sand bed needs to be removed from a reef aquarium, and there are organisms that cannot be relocated out of harms way, the following precautions may be useful based on the principles detailed in previous sections, although I've not tested any to see how effective they are:

A. Remove delicate organisms from the tank system, if possible.
B. Perform the change when the lights are as bright as possible, preferably near the end of the light cycle. The lights drive the O2 concentration higher, speeding the oxidative removal of hydrogen sulfide, and the light itself will catalyze the oxidation of H2S.
C. Maximize aeration. A high oxygen level drives hydrogen sulfide oxidation, and high aeration will drive some off as volatile H2S gas.
D. Add an iron supplement to help catalyze oxidation of hydrogen sulfide and the precipitation of ferrous and/or ferric sulfide. Use one chelated to an organic; either ferrous or ferric iron will work.
E. Pass the water over iron oxide/hydroxide (GFO) to convert hydrogen sulfide to elemental sulfur.
F. Pass the water over activated carbon, which may bind some sulfide, and may also catalyze the oxidation. If forced to choose between carbon and GFO, I'd pick the GFO media."

 

[jdg]

Thank you for your email; I looked at the article but I am still not sure if I should begin removing the white mats and continue dosing?

One thing I forgot to mention is that I don't have any sand. It's a very high flow starboard system.

My sump has a partition that I use as a detrius sink to make it easy to vacuum out particulate/etc. Right now, the whole bottom of it is looks like it has a layer of snow/frost on it. It's probably a 20"x24" footprint.

Also, how dangerous is this for the kids/pets? Should I have them stay elsewhere until this is resolved?

 

[HighlandReefer]

The human nose can detect hydrogen sulfide at very low levels before it reaches toxic levels. After a while, hydrogen sulfide deadens the human nose sences. Without a proper test kit you really don't know the levels, but can only guess. The fact that you can smell it through out the house is not a good sign IMHO. Since it is a gas that is heavier than air, then the lower levels of the house should have highest concentrations, but the air circulation system may be in the lowest level or basement which will throw it throughout the house. This will also dilute the gas as well. It may be a good idea for safety sake to get the kids out of the house, until you can get the house aired out to the point where you can't smell the odors after re-entry, remember if you stay in the house, it will deaden your nose sences.

From an article:

"How can hydrogen sulfide be detected?

The nose is the best source. Hydrogen sulfide is one of the few water contaminants that human senses can detect at low concentrations. The odor is most noticeable when water is first turned on or heated. Thus, a shower can be an unpleasant experience.

The odor can be detected at levels as low as 0.5 parts per million. At less than 1 ppm, hydrogen sulfide will give water a musty odor. At 1 to 2 ppm, it will have an odor similar to rotten eggs. Levels are usually less than 10 ppm.

Since hydrogen sulfide is dissolved in water and vaporizes from it, samples must be analyzed at the site or stabilized before sending them to a laboratory. Several test kits are available for less than $10"


From Wiki:

"Toxicity

Hydrogen sulfide is considered a broad-spectrum poison, meaning that it can poison several different systems in the body, although the nervous system is most affected. The toxicity of H2S is comparable with that of hydrogen cyanide. It forms a complex bond with iron in the mitochondrial cytochrome enzymes, thus preventing cellular respiration.

Since hydrogen sulfide occurs naturally in the body, the environment and the gut, enzymes exist in the body capable of detoxifying it by oxidation to (harmless) sulfate.[10] Hence, low levels of hydrogen sulfide may be tolerated indefinitely.

At some threshold level, believed to average around 300–350 ppm, the oxidative enzymes become overwhelmed. Many personal safety gas detectors, such as those used by utility, sewage and petrochemical workers, are set to alarm at as low as 5 to 10 ppm and to go into high alarm at 15 ppm.
A diagnostic clue of extreme poisoning by H2S is the discoloration of copper coins in the pockets of the victim. Treatment involves immediate inhalation of amyl nitrite, injections of sodium nitrite, inhalation of pure oxygen, administration of bronchodilators to overcome eventual bronchospasm, and in some cases hyperbaric oxygen therapy (HBO). HBO therapy has anecdotal support and remains controversial.[11][12][13]

Exposure to lower concentrations can result in eye irritation, a sore throat and cough, nausea, shortness of breath, and fluid in the lungs. These effects are believed to be due to the fact that hydrogen sulfide combines with alkali present in moist surface tissues to form sodium sulfide, a caustic.[14] These symptoms usually go away in a few weeks.

Long-term, low-level exposure may result in fatigue, loss of appetite, headaches, irritability, poor memory, and dizziness. Chronic exposure to low level H2S (around 2 ppm) has been implicated in increased miscarriage and reproductive health issues among Russian and Finnish wood pulp workers,[15] but the reports have not (as of circa 1995) been replicated."

 

[HighlandReefer]

Perhaps the bacterial biofilm seen is high in anaerobic sulfur bacteria, so I would remove it and follow Randy's recommendations to help remove the hydrogen sulfide, like using, GFO and lots of Carbon. Plus good water filtration.

Perhaps carbon dosing is increasing the growth of the sulfur bacteria, so I would stop for now and see how it goes.

If you have any stagnet open pvc pipes in your tank, they can be a source of high hydrogen sulfide production.

 

[jdg]

You are correct in your assumption that the return for the circulation system in the house is at a low level, so that could certainly be an issue as well.

I will cease dosing and begin removing the biofilm/frost/white mats/etc. I also have like a half gallon of purigen I can run for a bit.

Should I continue running the biopellets? Or should I pull those offline as well?

I didn't realize an aquarium could produce so much H2S!

 

[HighlandReefer]

Not sure about the biopellets. If you have a lot of biofilms on the pellets they can be anaerobic as well. Clean them out regularly will help keep in aerobic. When you open the biofilter, if a problem I would think the sulfur smell would be strong.

Ventilating the house with fans points outside should bring levels down pretty quickly. Watch closely for these signs:

Exposure to lower concentrations can result in eye irritation, a sore throat and cough, nausea, shortness of breath, and fluid in the lungs. These effects are believed to be due to the fact that hydrogen sulfide combines with alkali present in moist surface tissues to form sodium sulfide, a caustic.[14] These symptoms usually go away in a few weeks.

 

[jdg]

Okay, I cleaned all the film out from the sump and I also cleaned out the skimmer and the biopellet reactor (it needed to be recharged anyways). Flow looks good in all areas, though I am noticing more "frost patches" elsewhere in the main display. I don't know if they've been there for the last few days, or if I'm just a little more sensitive to it now though.

I dropped .5L of Purigen and 1L of Matrix Carbon in the returns as well.

I also setup the skimmer to skim wetter (it was pulling out black mud) and did another 10% water change.

With the dosing stopped and feeding cutback, will the remaining biofilm just fade away? Or do I need to consciously remove it?

Thank you again for your assistance.

 

[HighlandReefer]

If the biofilm looks unacceptable in the DT, I would remove it.

Hopefully by now, the sulfur odors are under control.

 

[jdg]

It's tough to remove from the display, but I am working on it. The odor is much improved, but still not completely gone near the tank. The tank was cloudy again this morning, but I suspect that is due to the biopellet recharge.

I also noticed small white patches starting up again in the sump -- either from items that washed down from the main display or new little colonies of film flowing. I'll keep an eye on it and remove what I can as often as I can. The good news is that nitrates are falling off a cliff.

 

[HighlandReefer]

The good news is that nitrates are falling off a cliff.

:lol:


Sounds like the tank is now going in the right direction.

 

[jdg]

I guess those red solo cups full of vinegar did the trick. :lol:

 

[jdg]

I might have spoken too soon: the odor is back and the water is cloudier today than it was yesterday -- could it be due to the disturbance of all the biofilm?

The skimmer is pulling out some pretty thick foam and dark (ie: black) skimmate.

Maybe the recharge of the biopellet reactor had something to do with it as well? Should I shut that down?

If the nitrates disappear, so does the food source, correct? So the bacteria should have nothing to produce H2S from, right?

 

[HighlandReefer]

Fish excrement and fish food are being constantly added as a food source.

 

[jdg]

Fish excrement and fish food are being constantly added as a food source.

Understood; but the outbreak was likely caused by the overfeeding and the carbon [over]dosing. That being removed from the equation, the excrement and food should not be able to sustain the bloom, correct?

 

[bertoni]

Some fresh carbon might help with any remaining odors. The bloom should go away when enough nutrients are exported from the tank. The measured nitrate level won't help all that much, since there are other forms of nutrients.