my rice experiment

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bertoni said:
Okay, some quick googling lead to some hits on marine species of Nitrobacter and Nitrosomonas, so I'm not completely forgetful. :)
Click to expand...

There are so many marine bacteria and bacteria that can and will adapt to different environments that it does not surprise me. I read somewhere that the majority/common marine nitrifying bacteria were nitrococcus and nitrosococcus.
 
You used "anoxic" in the sentence about bacteria, along with aerobic and anaerobic, and I didn't understand what you meant by that.
 
then we can say that the bacteria leaving the reactor with rice and reaching the water column, may also serve food?

is also possible to keep the train of rice and it is maintained at the maximum of anoxia can only passing through the reactor an amount of 3.5 liters per hour?
 
Update

Update

Day 17
Orp 273mV
Ph 8.2
No3 5ppm
Po4 detecible but not measurable
Once again today my po4 test kit did not read zero, however it was not enough of a color change to indicate a reading of .1 . Also my nitrates went up slightly from 2.5 to 5 ppm. I would really like to know the cause of this. All my corals look good and have great polyp extension. Still cleaning my glass every 2-3 days and I haven't removed any more cheato from my sump. Also the low orp is starting to worry me. Does anybody else monitor their orp level?
 
Here is my conversation with Ron Shimek regarding the heavy metals in rice.

Dear Ron,
there is heavy debate the last days regarding the use of rice as a source of organic carbon dosing to cultivate hypoxic bacteria to remove Nitrates and phosphates from the water column. This has been proven to work as a nutrients control method.

The main reason of the debate and the suitability of rice is it's contents in heavy metals such as copper, zinc, magnanese and iron.

We have 3 different sources that measure these metals in NSW. One is provided by you on reefkeeping magazine,
http://reefkeeping.com/issues/2002-02/rs/feature/index.php
http://ozreef.org/library/tables/natural_s...omposition.html
http://reefkeeping.com/issues/2005-11/rhf/index.php

Concentration in NSW from these 3 links:
Copper
380ng/L=0.38ppb
0.0001ppm=0.1ppb
0.09ppb

Iron:
140 ng/L=0.14ppb
0.000055ppm=0.055ppb
0.02ppb

Manganese:
165 ng/L=0.165ppb
0.0001ppm=0.1ppb
0.010ppb

Zinc:
590 ng/L=0.59ppb
0.0005ppm=0.5ppb
0.014ppb

From here we can find the concentration of these metals in one cup of rice:
http://nutritiondata.self.com/facts/cereal...nd-pasta/5721/2

Per 185g:
Copper: 0.3mg
Iron: 3mp
Manganese: 1.8mg
Zinc: 2.2mg

For a rice reactor we use half a cup for about 300 litres of seawater.

So if I m not wrong with my calculations, this quantity should be translated to:

Copper: 0.15 mg/300L = 0.0005mg/L
Iron: 1.5mg/300L= 0.005mg/L
Manganese: 0.9 mg/300L=0.003mg/L
Zinc: 1.1mg/300L=0.0037mg/L

Copper: 0.5ppb
Iron: 5ppb
Manganese: 3ppb
Zinc: 3.7ppb

The above will be gradually release as the bacteria consume the rice.
So here are our questions:
What will happen to these metals?
1) will they be bounded by activated carbon?
2) will they be consumed by the bacteria on the rice?
3) will they be removed by the skimmer?
4) will they stay in the water column?

In case they stay in the water column is this amount high enough to be detrimental to the health of animals in a reef tank? We assume that we will need to change the rice every 2 months.
I have read that copper concentration of 10ppb decreases the sea urchin larvae survival to 48hours and at 100ppm it is lethal (your article again: http://reefkeeping.com/issues/2003-03/rs/feature/index.php)
Click to expand...

Hi,

You asked,

So here are our questions:
What will happen to these metals?
1) will they be bounded by activated carbon?
2) will they be consumed by the bacteria on the rice?
3) will they be removed by the skimmer?
4) will they stay in the water column?

In order:

1) Nobody knows,
2) Nobody knows,
3)Nobody knows, but probably,
4) Nobody knows, but probably some will.

The reasons the questions are answered this way is that nobody has followed this type of chemistry in a reef tank by actually measuring the fates of toxic heavy metals. The tests for these metals are expensive and difficult to do, as the amounts of materials that one is testing for are so very tiny.

The data in my article - now several years old - came from current scientific research articles at the time of writing. Those articles have been supplemented over the intervening time, with more data describing how absurdly and awfully toxic very small amounts of these metals are. Plain and simply any concentrations above those found in natural sea water kill animals. Low excessive doses kill slowly, higher excessive doses more rapidly. The metals also accumulate in animal tissue and cannot be purged, so once introduced to the animal, they are there until the animal dies, whereupon they get released back into the system.

Now as to the rice...

You only know the concentrations of these materials in any batch of rice if that SPECIFIC batch is tested. The amount of these metals in rice will vary from rice paddy to rice paddy due to variations in the soil. The metals concentrations may be very high or very low depending on the source of the rice, as these metals are more-or-less passively carried up in the plants with the ground water the plant uses.

The bottom line, I am sorry to tell you. is this: The rice may be a good source of nutrient for your bacteria, but you will not be able to test for any of these toxic materials adequately in either the rice or your tank. The most sensitive tests are called "bioassays" and involve putting a test animal (usually a fish, worm, shrimp or clam) in a solution containing the metal and seeing if that test subject sickens or dies. In essence, you will be running your own bioassay test by using the rice.

The first notice you may get that the metals concentration in your tank is high (from metals leached out of the rice) may be when your systems start to experience unexplained mortalities.

Sorry not to be more definitive, but that the situation at the moment.
Click to expand...
 
I believe Ron made his point regarding the high heavy metal levels found in all the salt mixes we use, as well as the heavy metals we add as contaminates when maintaining calcium, alk and mag & the heavy metals added by fish food. These heavy metals are constantly being added to our reef systems.

Obviously the heavy metals are removed from our reef systems in some manor, such as becoming tied with organics & then being removed by skimming and GAC, or everything in the tank would die from really high levels. One thing I found alarming is that in Ron's tests & in one other test completed, the tanks with bare bottoms had extremely high levels of heavy metals. Something to think about.

We don't have the expensive equipment to measure the metals. Randy has stated & I agree that supplementing the heavy metals can be dangerous. The research finds that our tanks are already at heavy metal levels without additional supplementation where it causes problems for many organisms commonly found in our systems. Yet hobbyists supplement these heavy metals for color changes and in some cases with good results. Go figure. :D

In addition, from research, the concentrations of heavy metals it takes to cause problems for our organisms varies quite a bit depending on the coral & symbiont species and in many cases they have found that the same specie can have quite a variance in what levels it can tolerate. Obviously genetics has something to do with it and this is where the current research is going. FWIW, they are finding that the heavy metals effect both the symbiotic algae & bacteria and the coral tissue negatively at high enough levels. Too high a levels of heavy metals will cause population shifts in the symbionts as well as their expulsion (bleaching). What happens to the heavy metals introduced into the coral tissues and how they react are currently being studied. :)

They have found that once the heavy metal levels in the water column are reduced, so do the same levels within the symbionts and coral tissues. So there must be some mechanism that coral & symbionts use to reduce the metal levels accumulated. Ron has stated above that for animals they can't purge it. I'm not sure about fish, but I would suspect that the metals can be purged, at least to some degree. Copper treatments for fish are at very high levels and this does not seem to have too bad effects on them. Granted, the heavy metal levels can increase up through the food chain. :hmm3:
 
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Something you may find interesting. When we think of bacteria acting on carbon sources, we may mistakenly forget about the fact that bacteria form biofilms, which is like a city compared to how we live. There is usually quite a few species of bacteria present in a biofilm. The type of bacteria present as disused by Phil will align themselves in the appropriate areas within the biofilm. I would think bio-films would play a big role in the rice reactor as well as other carbon source reactors and liquid carbon source applications. This is not to discount the bacterial action that will take place in the water column. :)


Biofilms: Microbial Life on Surfaces
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2732559/

From it:

Biofilm Architecture

Tolker-Nielsen and Molin noted that every microbial biofilm community is unique (43) although some structural attributes can generally be considered universal. The term biofilm is in some ways a misnomer, since biofilms are not a continuous monolayer surface deposit. Rather, biofilms are very heterogeneous, containing microcolonies of bacterial cells encased in an EPS matrix and separated from other microcolonies by interstitial voids (water channels) (44). Figure 3 shows a biofilm of P. aeruginosa, Klebsiella pneumoniae, and Flavobacterium spp. that has developed on a steel surface in a laboratory potable water system. This image clearly depicts the water channels and heterogeneity characteristic of a mature biofilm. Liquid flow occurs in these water channels, allowing diffusion of nutrients, oxygen, and even antimicrobial agents. This concept of heterogeneity is descriptive not only for mixed culture biofilms (such as might be found in environmental biofilms) but also for pure culture biofilms common on medical devices and those associated with infectious diseases. Stoodley et al. (45) defined certain criteria or characteristics that could be considered descriptive of biofilms in general, including a thin base film, ranging from a patchy monolayer of cells to a film several layers thick containing water channels. The organisms composing the biofilm may also have a marked effect on the biofilm structure. For example, James et al. (46) showed that biofilm thickness could be affected by the number of component organisms. Pure cultures of either K. pneumoniae or P. aeruginosa biofilms in a laboratory reactor were thinner (15 μ and 30 μ, respectively), whereas a biofilm containing both species was thicker (40 μ). Jones et al. noted that this could be because one species enhanced the stability of the other.
Figure 3
Polymicrobic biofilm grown on a stainless steel surface in a laboratory potable water biofilm reactor for 14 days, then stained with 4,6-diamidino-2-phenylindole (DAPI) and examined by epifluorescence microscopy. Bar, 20 μ.

Biofilm architecture is heterogeneous both in space and time, constantly changing because of external and internal processes. Tolker-Nielsen et al. (47) investigated the role of cell motility in biofilm architecture in flow cells by examining the interactions of P. aeruginosa and P. putida by confocal laser scanning microscopy. When these two organisms were added to the flow cell system, each organism initially formed small microcolonies. With time, the colonies intermixed, showing the migration of cells from one microcolony to the other. The microcolony structure changed from a compact structure to a looser structure over time, and when this occurred the cells inside the microcolonies were observed to be motile. Motile cells ultimately dispersed from the biofilm, resulting in dissolution of the microcolony.
 
Update

Update

Day 18
pH 8.0
PO4 <.1
NO3. 5-10 ppm :thumbdown:
Orp 283mV
Well I'm on day 18 of the experiment and I have to admit I'm a little perturbed. My NO3 is going up and I'm not too happy about that. I replaced the rice in my reactor 4 days ago and since then I'm seeing an increase in the very things I'm trying to keep out of my system. When I repacked my reactor I used 3/4 cups rice a bit more than the 1/2 cup I had used the first time. I figured I could add more as I already had a bacteria bloom and had fairly low n/p. Now I'm seeing a steady rise in NO3. I think I'm going to allow this to continue until this Saturday(day 21). If I see no reduction or level off in NO3 by then I will first try removing some rice to see if more rice is having a negative effect. If I still see continue to see a rise in nitrate I will have discontinue the experiment. I am still deciding at what level of nitrate I will cancel my experiment do a major water change,run purigen, gac, gfo and ask a club member for a bag of cheato. Other then a little color in my test kits my tank is looking ok for the most part. A few things I am noticing are that the crowns on my feather dusters are looking a bit sparse my two coco worms look fine however. I had a little lack of polyp extension this morning before my lights turned on. But after I feed my reef things perked right up. I am seeing a few corals do some funny color changing brighten up (green acro) pale out (Joe the coral) and turn green (purple monster). I really am caught up on the rise in no3. I did change out my skimmer but I'm using the same brand skimmer just the next size up. If anyone would care to speculate or throw out a nitrate level at which I should throw in the towel plz share. I was thinking if I cross 20 ppm, start to see rtn/stn, or bleaching I'm "calling it". Better to be safe than sorry.
 
Wow, I sound a bit frazzled in that last post water change, media, macro and all. I'm wondering if it's just taking some time for this batch of rice to take a culture. Just gonna have to see how it goes
 
icycoral said:
Wow, I sound a bit frazzled in that last post water change, media, macro and all. I'm wondering if it's just taking some time for this batch of rice to take a culture. Just gonna have to see how it goes
Click to expand...

Go back a few of pages and review the discussion forward a page or two. It may help you with your decision.

DJ
 
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