Wednesday, June 26, 2013

A comparison study of filtration systems ( Anoxic Vs All) By: Lio Stove , Castrezzato Italy

ED: I have painstakingly translated and placed all of Lio's blog test here so all can read about his testing of the Biocenosis Baskets. He was one person that though more about the hobbyists than himself. This is in memory of him and his work, may it never be forgotten.

Lio Stove AKA: Dr. Franco.

This study aimed to compare the results obtained from the comparison of the filtering capacity of ammonia, dissolved in a container, by the following types of filtration.

1) Filter anoxic
2) Traditional nitrifying filter 

3) Phytodepuration

In particular, the wetland is tested on 4 different species of aquatic plants to be able to better assess the ability of each filter.


It prepares a 1000 liter containers in which they are paid about 500 gallons of water from the aqueduct and the network has the following chemical values:

Ammonia / Ammonium total = 0 
Nitrites = 0
Nitrate = 2.7 (double-checked value)

 Phosphate = 1.94 (value rechecked) 
GH = 19
KH = 9
pH = 7.5
ORP = 155
Total Chlorine = 0.02

Then the container is poured ammonia (from household packaging) to obtain an initial value of 3.74 mg / l detected by digital photometer.

For proper mixing of the ammonia is introduced inside the container an air pump to airstone power of 35 l / min. 

It also predispose 7 waterproof plastic containers from the total volume of 65.7 liters and internal dimensions 51x33, 5 h, filled with 50 liters of water withdrawn from the container containing ammonia titrated, whose aeration is left active until complete water distribution in the seven containers.
In each of the containers are then stored:

# 1 container = 1 basket anoxic 28x28x19h cm
# 2 container = filter nitrifying Classic 

Iris pseudacorus = container # 3
Container # 4 = TIPH latifolia
# 5 container = water hyacinth
container = Elodea canadensis No.6
# 7 container = nothing (Control container) 

The volumes of filter No. 2 to No. 6 containers were conventionally set equal to the size of the volume occupied by anoxic basket. For plants that emerged or floating this volume is represented by the roots (see images below).

No. 2 is placed in the container of the filter material already activated (tuff grain size 4-6 cm). Each of the seven containers is equipped with artificial movement of the water produced by a pump Hydor Pico 600.

The plants in containers from No. 3 to No. 6 are stored in the bare-root baskets to emphasize their absorption capacity. All 4 plants have not been severed for over a month so that they are able to express the filtering capacity without interference given by the condition of traumatic transection. During the test is not porcederà any filling of the containers that presented in temperature or evaporation from consumption (those containing plants). All seven of the containers are placed under the translucent roof of a gazebo, sheltered from any rain or excessive sunlight. 

The test duration is 4 days, during which will be taken from 1 to 3 measurements of ammonia per day (of which the first 2 hours after the start of the experiment) for each container.

At the end of three days will be taken again the values ​​of:

- Nitrites
- Nitrates
- Phosphates
- GH
- KH
- PH
- Redox potential

to compare with those found at the beginning of the test.
At the end of the test will be made of Diagrams of all the values
​​considered made for each of the containers.

To run the tests we make use of chemical instrumentation provided by Hanna:

HI83203 Photometer bench model 
Portable pH meter model HI98127 
ORP metro laptop model HI98120

To test GH and KH test reagents used in the "Evening".


AMMONIA = ± 0.05 mg / L ± 5% of reading at 25 ° C 
CHLORINE = ± 0.03 mg / L ± 3% of reading at 25 ° C 
NITRATES = ± 0.05 mg / l ± 10% of reading at 25 ° C
NITRITE = ± 0.04 mg / L ± 4% of reading at 25 ° C 
PHOSPHATES = ± 0.04 mg / L ± 4% of reading at 25 ° C 

DAY 1 - Values ​​ammonia - Ore 12.30 - 08.26.2011 - First sampling

# 1 container = 2.81 
Container No. 2 = 1.86 
# 3 container = 3.56 
Container # 4 = 2.42 
# 5 container = 2.96 
Container No. 6 = 3.54
# 7 container = 3.68 

DAY 1 - Values ​​ammonia - 20.30 hours - 26/08/2011 - According to sampling

# 1 container = 1.63 
Container No. 2 = 0.46 
# 3 container = 3.00
Container # 4 = 2.95
 # 5 container = 2.33
 Container No. 6 = 3.05
# 7 container = 3.56 

DAY 2 - Values ​​ammonia - 9.00 pm - 27/08/2011 - Third sampling

# 1 container = 0.84 
Container No. 2 = 0.13 
# 3 container = 2.50 Container 
# 4 = 2.46
 # 5 container = 1.33 
Container No. 6 = 2.54
# 7 container = 3.52 

DAY 2 - Values ​​ammonia - Ore 13.30 - 27.08.2011 - Fourth sampling

# 1 container = 0.41 
Container No. 2 = 0.03 
# 3 container = 2.29 Container 
# 4 = 2.20 
# 5 container = 0.73 
Container No. 6 = 2.23
# 7 container = 3.52 

DAY 2 - Values ​​ammonia - Ore 21.00 - 27.08.2011 - Fifth collection

# 1 container = 0.19 
Container No. 2 = 0.14 
# 3 container = 1.86
 Container # 4 = 1.94 
# 5 container = 0.13
 Container No. 6 = 1.68
# 7 container = 3.41 

DAY 3 - Values ​​ammonia - Ore 21.00 - 08.28.2011 - Sixth sampling

# 1 container = 0.06 
Container No. 2 = 0.12 
# 3 container = 1.53 
Container # 4 = 1.62 
# 5 container = 0.09 
Container No. 6 = 1.10
# 7 container = 3.36 

DAY 3 - Values ​​ammonia - Ore 21.00 - 08.28.2011 - Seventh sampling

# 1 container = 0.07 
Container No. 2 = 0.07 
# 3 container = 0.91 
Container # 4 = 1.21 
# 5 container = 0.04 
Container No. 6 = 0.32
# 7 container = 3.25 

DAY 4 - Values ​​ammonia - Ore 12.30 - 08.29.2011 - Eight sampling

# 1 container = 0.06 
Container No. 2 = 0.10
 # 3 container = 0.42 
Container # 4 = 0.84 
# 5 container = 0.06 
Container No. 6 = 0.08
# 7 container = 3.21 

NO2 = 0 NO3 = 8.5 PO4 = 0.19 GH = 15 KH = 10 PH = 9.0 ORP = 104
NO2 = 0.02 NO3 = 11.2 PO4 = 0.55 GH = 18 KH = 9
PH = 8.3 ORP = 127
BOX # 3
NO2 = 0.02 NO3 = 8.0 PO4 = 0.16 GH = 16 KH = 9
PH = 7.8 ORP = 133
BOX # 4
NO2 = 0.01 NO3 = 7.5 PO4 = 0.25 GH = 17 KH = 10
PH = 8.0 ORP = 115
BOX # 5
NO2 = 0.01 NO3 = 9.7 PO4 = 0.02 GH = 14 KH = 18
PH = 8.5 ORP = 102
BOX # 6
NO2 = 0.05 (value rechecked)
NO3 = 11.0
PO4 = 0.09

GH = 11 KH = 5 PH = 9.1 ORP = 87
BOX # 7
NO2 = 0 NO3 = 7.6 PO4 = 0.10 GH = 15 KH = 9
PH = 8.1 ORP = 108

Lio Stove doing his test on the Anoxic Biocenosis Baskets.


CONTAINER No. 7 (Control)
The water level was not altered by obvious mechanisms of evaporation, so the water level is close to that at the beginning of the test set, taking into account that were also removed about 150 ml of water required as standard for the evaluation the photometer.
The values
​​of test start (water mains) are different from those at the end (tap water with added ammonia). Among these incongruous value of phosphate for no apparent reason has been a decrease (from 1.94 to 0.10).

The value of nitrate was increased interference affected the photometric test for the presence of ammonia (as confirmed by the documentation attached to the photometer). So the final value of nitrates is not trusted. There is also a slight decline in total hardness of the water that goes from 19 to 15, with increased pH and decreased (?!?) Redox potential. Ammonia has experienced a slight drop due to evaporation in relation to temperature and initial concentration.

PLANTS FILTER (6-3 containers)
The plants have reacted more or less quickly to the disposal of its ammonia, but also present uniformly conflicting data on what is known in the literature and from what I would like ammonia consumed by adsorption from the roots of the plant:

1) The constant presence of nitrite, which in the case of Elodea reach the highest level of 0.05 mg / l, together with high levels of nitrates, which would be expected as a result of a plant that feeds on hope, suggest that nitrification occurred predominantly through the work of nitrifying bacteria housed in the branching of the root derivations, with a surprising finding, given the fact that the values ​​of nitrate placed on increasing scale go hand in hand with the root development of these plants, further reinforcing the hypothesis of a nitrification external to the roots (known denitrification made from the plant to produce ammonium nitrate by its food, is within the roots for a biological process catalyzed by enzymes that perform work similar to denitrifying bacteria to the water environment outside). 

2) Each result confirms the plant-filter (with repeated examination) an increase in pH compared with a decrease of total hardness (usually the consumption of alkaline substances as a result of the metabolism of the plant or bacteria hosted on its roots produces a decrease in pH values).

The preponderance of oxidation reactions than the reduction that occurred in each container are the main reason for the decline, more or less important, the ORP values ​​of the containers that host-plant filter. The consistent decrease in the hardness values ​​is confirmed as a matter of metabolism produced by the plant itself or by nitrifying bacteria and that they need to fix carbon dioxide (CO2) to meet their carbon requirements.

CONTAINER n.6 (Elodea canadensis)
The plant came from a container placed in the sun for the most hours of the day, the waters of some units exceeded 30 ° C. The removal of ammonia inherent power of its own metabolism was therefore compromised in part because this plant has the optimum temperature for growth and development of the 23-28 ° C.
To this must be a partial ineffectiveness of the speed of removal of nitrogen compounds from the solution.

CONTAINER n.5 (Eichorn crassipes)
This plant-filter is the one that showed higher efficiency than the other observing the rate of consumption of ammonia. But part of this consumption is clearly supported by nitrification bacteria housed in its ramificatissime roots, as there is the presence of low levels of nitrite, but also high levels of nitrates compared to baseline values.

CONTAINER No.4 (TIPH latifolia)
The plant has a developed root system, but a small part of his development emerged. To this must be probably the low performance as evidenced by a high residual value of ammonia at the end of the test (0.84 mg / l).

BOX # 3 (Iris pseudacorus)
This plant is in this time of year having already completed the germination stage, which begins in early spring. Anc'essa shown a limited ability to extract nitrogen, an important part of which is converted by nitrifying bacteria anchored to its roots for the same reason aforesaid.

BOX # 2 (nitrifying filter)
The filter nitrifying reacted in principle as shown by practical experience from the use of biological filters pond hobby. That is an efficient (the first among all the filter systems analyzed here) rapid removal of nitrogen expressed by a greater steepness of the curve in its initial phase (high concentration of ammonia) and a less steep curve in its final phase ( low concentration of ammonia).

The increase in the value of total hardness, compared with the start of the test is an expression of the organic substrate used for the adhesion of bacteria, which in this case was represented by the tuff. This is a limestone that releases calcium carbonate, which is particularly rich in a reverse process to that which produced from water solutions rich in this mineral.

The partial collapse of values
​​Rodox is compatible with the prevalence of oxidation reactions that occurred in the container.
Not unlike what happened to the plants filter the pH is here increased despite the decline of the carbonates produced by oxidative metabolism.

BOX # 1 (anoxic filter)
The ammonia from the anoxic filter container has reached values ​​close to zero with a speed second only to that of the nitrification filter. It 'should now understand what happened to this substance.

According to the principles governing the action of purifying a basket anoxic, ammonia enters the basket facilitated by a gradient "magnetic-like" produced by a difference of positions within the basket negatively charged, due to the presence of clay and laterite , rich in positive charges from the outside due to the

accumulation of ammonia (NH4 +).

Initially it meets the outer layer which, being in contact with water with high levels of oxygen, aerobic bacteria obliged normal hosts (Nitrosomonas and Nitrobacter) that use oxygen to carry out their metabolic action, thus depleting the water.

Gradually deepened in the basket that is increasingly lacking in oxygen.
Reaching the core of the basket, almost devoid of oxygen, the water contains ammonia, nitrites and nitrates produced by the metabolism of nitrifying bacteria outside. These items become a source of oxygen for facultative anaerobic bacteria that dwell inside the basket with anoxic environment that was formed, and then use the nitrates and nitrites to ammonia and subsequently converted into molecular nitrogen.
This mechanism clearly explains the behavior of the values
​​at the end of this container tests: virtually all the ammonia is processed and then is absent from the solution. Although nitrites are absent.

The presence of nitrate suggests that the advent of oxidative metabolism is the work of nitrifying bacteria. Lowering the value of phosphate compared to baseline values, but also compared to those obtained from tests at the end of nitrification filter, argues in favor of a consumption basket directly from anoxic operated as reported by the experiences of hobbyists who have adopted this system for filtering their pond.

The rise of the KH one point suggests that the process of denitrification has released calcium carbonate. Given the presence of the two processing mechanisms in the basket anoxic ammonia (nitrification and denitrifying) is unclear how the process of denitrification is quantitatively greater than nitrification. This fact is evidenced by the small (only seven baskets in the case examined) increased by one unit KH.

This is because after the denitrification reaction, there is a production of stoichiometric 3.57 mg of alkalinity expressed as CaCO3 per mg of NO3, while it consumes twice as CaCO3 in nitrification. In order to increase a unit of KH, the denitrification reaction must be at least double those of nitrification. This fact is also evidenced by a significantly lower nitrate content compared to the filter housing nitrification in the absence of another factor of consumption of nitrates (such as plants or specific adsorbent resins).


The validity of a filter system for a pond populated by koi well not be based solely on the processing speed of organic detritus produced by the fish, but must provide coverage of this activity throughout the period of high metabolic system of fish.
A pond that bases its filtering capacity only on the principle of wetlands may not be appropriate to dispose of the organic load produced by the fish in the early and late periods of hot weather. In fact, when the fish start waking up as early metabolic values ​​of temperatures of 8-10 ° C, corresponding to an atmospheric temperature of about 12-15 ° C, the season is not yet suitable for optimal growth of aquatic plants as mostly still dormant winter. For the same reason the late summer season with its high temperatures did not favor their growth.

It is therefore likely to submit the koi to inadequate levels of water pollution hazardous to their health, when in fact frankly lethal.
The nitrifying filter operates on the basis of the detoxification of the two major groups of bacteria: Nitrosomonas and Nitrobacter. However these are subject to the limitations of their maximum metabolic efficiency mainly of a narrow range of pH values ​​(7 to 8.5) values ​​that rarely has a majority of the lakes. The activity of these bacteria also occurs as optimum temperatures ranging from 18 to 25 ° C, leaving dangerously discovered the period beginning and ending of the hot season, it is particularly dangerous because it corresponds to the period of maximum metabolic activity of the koi. These bacteria are also sensitive to osmotic shock produced by the presence of salt (often used as a pesticide product), the presence of chemicals and low oxygen concentrations typical of the summer to raise the temperature of the lakes.

The filter consists of an anoxic defined biocenosica essential unity.
Wikipedia gives this definition of biotic communities:
"[E 'a term which] derives from Greek words βιος (bios = life) and κοινος (koinosis = common) and indicates the community of species in an ecosystem that lives in a certain environment, or, rather, in a given habitat (from the greek life and τοπος βιος = = place), ie an area in which the physico-chemical and environmental conditions are constant. "

This definition is perfectly corresponds to what has been shown in tests for this unit ball.
Nitrifying bacteria work on it and facultative anaerobes in mutual cooperation, the first feature is on the outer layers of the clay forming the basket, while the second reserve interior spaces where the concentration of oxygen is close to zero.

The facultative anaerobic bacteria are a diverse group of bacteria extracted from the genera Pseudomonas, Micrococcus, Archromobacter, Bacillus, Alcaligens. They are already active at temperatures of 5-6 ° C is 
actively resisting to temperatures above 30 ° C, are best at pH range higher than those of nitrifying bacteria (from 7.0 to 9.0), are less sensitive with salt and chemicals, and in no way limited by the low concentration of dissolved ossigneo (therefore do not need forced ventilation of the filter).
These types of filter systems, you are considered for display purposes as three different realities, however, this experiment has shown how a system can also take advantage of the other, except that Filter and Filter anoxic nitrifiers have opposite mechanisms that make them incompatible in part to the role that must play. Fitodepurante a filter acts not only due to direct adsorption of the plant, but as we pututo observe, even by the myriad of bacteria that can be hosted in the dendritic ramifications of its roots.

Both the filter that the anoxic nitrification may also benefit from the assistance of the plants to perform their function of purification: the filter nitrification produces nitrate which can then be used directly by plants to complete the cycle, while the anoxic filter can hold the center of each place the basket to the surface of the filter plant where it will find wide growth through the nourishment offered by the laterite ore in it.


The chart below analyzes the consumption rate of ammonia in various containers from concentrations to those likely to be found in a pond that is below the 0.4 mg / l.
Although the analysis of the complete graph shows a faster consumption of ammonia from the filter made anoxic nitrification compared to the filter, observing the slopes of the lines obtained here shows how the filter and the filter anoxic nitrification have the exact same speed for the disposal of ammonia while the plants are in some cases even faster (and Iris pseudacorus Eichorn crassipes). 

The filtering system is not theoretically anoxic unprecedented in the literature on urban waste water treatment plants or reservoirs already considers this an effective technique Nitrification-denitrification simultaneously. What is new is having guessed what could be the material (ie the one that clay and laterite) contained in the basket that could lay the basis for facultative anaerobic bacteria colonization, and have concentrated in a small space work Bacterial co-operation, making it compatible, and in some cases competing, compared to the volume of conventional filters pond.


This test is actually begun a month ago and was interrupted almost immediately for errors in the experimental protocol. An aerator was placed solely in the nitrification filter medium is oxygen, this has produced a series of changes that have translated into very different results from what is the practical reality of each of the tested filters: the filter despite the contribution of nitrification Oxygen has not shown greater efficiency and speed of action purifying than those obtained in this trial. While it is significantly higher evaporation produced by the movement of the bubbles. 

All baskets were also placed completely in the sun instead of under a protective roof which suffered greater evaporation in general but also reached unfavorable temperatures (above 32 ° C) to achieve optimum filtration.

During the test had also rained and the containers were spiked rainwater thus changing the actual concentrations of solutes. Compensate for their handling of water in the filter housing by National nitrifying but completely absent in the other containers produced an inconsistent use of ammonia in each of these.

The container then anoxic filter was enormously difficult to dispose of ammonia, since evidently the effect of "magnet" exercised the basket biocenosico working in close proximity to its perimeter. At the end of the third sampling, which in this test reached values
​​around zero ammonia, then the anoxic filter was disposed of only half of the organic load.
This fact is further corroborated by a similar experiment conducted by me a year ago for which the anoxic basket placed in a container of its exact size has been shown after three days, in which no intermediate measurements were made of ammonia, the complete absence of this.

The delicate balance that is slow and generates a filter in place to mature, whatever it is, however, is ill- suited to the sudden change of condition represented by an anoxic removal of the basket, the tuff or plant whatever you want from its natural place.
The results of this test should not be taken with absolute value and a true test should instead be evaluated "in vivo" after each filter has established with the wonderful nature of that balance letezza but determined to maximize the capabilities of filtering each of the systems reviewed.

Upcoming future tests can be done to evaluate different aspects of the differences in approach and filters so that more and more reliable results unveil the wonderful set of rules that govern the proper conduct of an ornamental pond. This I want to be a trial "open-track" performed by a simple fan of this hobby sector that does not give up to have their fish to a life acceptable provided by a filter that is not optimal efficiency and content in the expenditure and the management. 


To all the people who believed in the main, directly or indirectly supported this trial.
First to Dr. Kevin Novak, to whom be the warmest thanks for giving us this piece of his professional life, as 
well as moral support towards initiatives of this blog for the spread of a truly innovative filtration pond.

A special thanks to those who have made the experiment possible with technical equipment: - Hanna Instruments Mammana and Savior in the person of Dr. Valentine Colzani.
- Opirob for logistical support and changes to the protocol.
- Tia84 containers provided for the filters.

- To all those who have believed in Italy in the anoxic filter adopting it with your eyes closed and thus further stimulating my curiosity and motivation.
- A blog of all employees who have believed and supported this first phase of the project.

Finally, but not the last, my grandchildren rigraziamenti Resconi Alice, Claudia, and Francis, for practical assistance in the experiment (no one like them is able to properly and diligently perform the various and delicate phases of the measurement with the photometer ).

..... and my Dizzy, holy woman!

 <b> Related stories:

Anoxia FILTER (FILTER ANOXIC by Dr. Kevin Novak) WHY 'HAVE A FILTER Anoxia
CLAY AND LATER (materials for the anoxic filter) HISTORY OF THE FIRST FILTER anoxia (Novak) ITALIAN TEST OF FILTER NOVAK 

Anoxic Filtration Book... Still free on Apple's iBook store
This is to inform everyone on a new way of obtaining the Anoxic Filtration System’s CD-book at Apple’s iBook Store.

If you have an Apple iPad, iPhone or iPod you can now download the book for free from the Apple iBook Store on your computer with iTunes. The Anoxic Filtration System CD-Book has been converted with the help of Apple’s iBook Author into a very colorful full version of the original CD-Book. Easier to read and page through without the breaking up of pages. Any page of the book can now be looked up easily and fast for reference when needed.

Anoxic Filtration System by Syd Mitchell, Tony Ruiz & Dr Kevin Novak

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