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  • I accept the point about water being an excellent solvent and it reaching a point where the ‘good solubles’ are depleted and the ‘bad solubles’ having accumulated to unacceptable levels.

    I cannot get my hands on the studies right now, but I read about the H2O molecules in structured water (aka living water, aka revitalized water) being arranged differently (yerrag’s point) and it having lower surface tension (possibly the same point seeing that surface tension could be a function of how molecules are arranged).


    Does lower surface tension translate into better off gassing properties and faster O2 absorption? There are commercially available devices that claim to ‘produce’ structured water in ponds - no, I am not the guy that falls for every Koi fad but I am the guy that continually looks for better ways of running my pond.


    I tried starting a thread on the relative density of ammonia, but seeing that I am new to this forum my thread must first be moderated. Ammonia has a lower relative density than water (at pond temperatures). Take that, add my limited knowledge of chemistry and you have ammonia floating at the pond surface. Does that mean I block the bottom drains and water change only through the surface skimmers? It does make sense to dump the most polluted water from the system when doing the weekly water change. If I am on the right track, we should understand the relative densities of the different pollutants in the pond. If my 25% solution to pollution dumps the water with the highest pollutant content, then I may in fact have a 35% solution to pollution (although my water bill and the environment only paid the 25%!).

    Comment


    • The percent of ammonia can be soluble with water at a certain temperatures. Usually ammonia hydroxide has 28% ammonia content in water. In ponds where ammonia is just measure only in ppm because the ammonia release is by koi in the pond are easily miscible with the water moved and circulated by pumps and aerations. You can do a simple test by getting water on top or at the bottom of the pond and the ammonia reading will be the same.

      I would not bother with blocking the bottom drains. In fact bottom drains push waste that release ammonia going to a settlement chamber that gets removed by the biological filters.

      Comment


      • Originally posted by Jacques View Post
        I accept the point about water being an excellent solvent and it reaching a point where the ‘good solubles’ are depleted and the ‘bad solubles’ having accumulated to unacceptable levels.

        I cannot get my hands on the studies right now, but I read about the H2O molecules in structured water (aka living water, aka revitalized water) being arranged differently (yerrag’s point) and it having lower surface tension (possibly the same point seeing that surface tension could be a function of how molecules are arranged).


        Does lower surface tension translate into better off gassing properties and faster O2 absorption? There are commercially available devices that claim to ‘produce’ structured water in ponds - no, I am not the guy that falls for every Koi fad but I am the guy that continually looks for better ways of running my pond.


        I tried starting a thread on the relative density of ammonia, but seeing that I am new to this forum my thread must first be moderated. Ammonia has a lower relative density than water (at pond temperatures). Take that, add my limited knowledge of chemistry and you have ammonia floating at the pond surface. Does that mean I block the bottom drains and water change only through the surface skimmers? It does make sense to dump the most polluted water from the system when doing the weekly water change. If I am on the right track, we should understand the relative densities of the different pollutants in the pond. If my 25% solution to pollution dumps the water with the highest pollutant content, then I may in fact have a 35% solution to pollution (although my water bill and the environment only paid the 25%!).
        The density of ammonia is a topic I do not recall being discussed. I am aware that as temperatures rise, ammonia in water will volatilize, but I have not read anything about ammonia molecules separating from water molecules to stratify in a pond. Probably need to consider the differences between ammonia ans ammonium ions. I think we need more solid information before throwing out the old conventional wisdom that water at the bottom is the 'dirtiest'.

        Comment


        • Originally posted by sacicu View Post
          You can do a simple test by getting water on top or at the bottom of the pond and the ammonia reading will be the same.
          I never have detectable levels of ammonia (unless the old girls surprise me with some early morning spawning which they manage despite my best efforts at winter fasting). But this is not only about ammonia. It is about all the pollutants in the water. I am not aware of test kits in South Africa that offers the needed resolution to identify small concentration differentials in the water column (irrespective of the pollutant).

          But thank you nonetheless for the suggestion. I have tried it on KH, nitrites and nitrates but without success.

          Comment


          • If you are a current contributor to this thread or an experienced koi keeper, please ignore this post.

            My previous post referred to the resolution of a water parameter test kit. If you are a casual reader of this thread and do not know what is meant by the resolution of testing equipment, then read on.

            If, for example, a pH testing kit can pinpoint pH to say either 7.0, 7.1, 7.2, 7.3, 7.4 or 7.5 then this test kit has better resolution than a second testing kit that only pinpoints pH to say 7.0, 7.5, 8.0 or 8.5

            Not to be confused with accuracy. An accurate test kit reads a pH of 7.0 when actual pH is 7.0. Inaccurate test kits read pH of 7.0 when actual pH is 7.3 (as an example).
            Last edited by Jacques; 03-07-2017, 03:28 AM. Reason: typo's

            Comment


            • Chemical stratification in Koi ponds seem unlikely due to sediment management and high water turnover rates. What is interesting to note is that, according to the below study, chemical stratification does take place (even in shallow waters), unless man intervenes.

              Back to indiscriminate water changes

              Extracts from a study in Thailand below:

              From https://link.springer.com/article/10...071-015-0113-y


              Shallow aquaculture ponds undergo diel cycles of thermal and chemical vertical stratification (Losordo and Piedrahita 1991).


              Pond sizes ranged from 0.16ha to 0.64ha (17000 ft – 69000 ft), with depths of 0.8m – 2.0m (2.6ft – 6.5ft).


              Stratification and water turnover is known to occur in tilapia fish ponds in Northern Thailand (Sriyasak et al. 2013).


              Altogether, 660 samples of fish pond water were collected for water quality analysis (15 ponds × 11 months × 4 samples) between May 2013 and 2014.


              Water samples were collected 20 cm (8") below the surface and 20 cm (8") above the pond bottom during stratified and de-stratified conditions.


              Chemical analyses were carried out for total ammonia-nitrogen (TAN) and chlorophyll-a according to standard methods (APHA 1980).


              The highest water temperature observed was 38.0 °C (100 F) in the hot season, and the lowest was 18.3 °C (65 F) during the dry season.


              Stratification usually began from 14:00 (2pm) to 16:00 (4pm).


              In a few instances however, no stratification was observed. The reasons for these instances include: exchanging of pond water and the use of aerators.


              In the bottom layer, TAN concentration was higher than surface water. This was likely due to the accumulation of nitrogen in the sediments (Hargreaves 1998; Kaggwa et al. 2010).
              Last edited by Jacques; 03-07-2017, 04:02 AM. Reason: converted Celsius references to Fahrenheit

              Comment


              • This study involved a good bit of work to support commonly understood temperature and dissolved oxygen stratification. The interesting aspect is that these were relatively shallow ponds (some only about 3 feet deep and averaging about 4 feet in depth) and we know they are heavily stocked. The movement of fish did not prevent stratification, giving added emphasis to the importance of aeration. I am not so sure about the total ammonia nitrogen (TAN) stratification element of the study. There was only a very slight difference in concentration, except in the so-called 'integrated' ponds where waste from livestock and poultry operations was dumped in the ponds (presumably to encourage phytoplankton growth??). Given that the evidence of TAN stratification was so slight in most pond types, I am doubtful about any conclusion being drawn. The speculation that TAN was higher at the bottom due to accumulation of waste and sediment is not helpful. That could be because the emission of TAN by the wastes takes time to spread to upper water levels rather than some other factor, or it could be that TAN is less in the higher temperature stratum. All sorts of theoretical reasons could exist, including volatilization at the surface. There was no effort to identify a reason or reasons, and the substantial differences in measurements between the 'integrated' ponds and other types of ponds raises questions which were ignored.

                Still, the key thought is consistent with conventional wisdom for koi pond maintenance:

                "Fish culture system and depth of pond had significant effects on TAN. In the bottom layer, TAN concentration was higher than surface water. This was likely due to the accumulation of nitrogen in the sediments (Hargreaves 1998; Kaggwa et al. 2010). Water de-stratification [such as by aerating] resulted in TAN concentration increasing at the surface layer; consequently, the diffusion of ammonia into the water column created a nutrient source to support the proliferation of phytoplankton (Hargreaves and Tucker 2004)."

                Keep waste out if the pond, dump settlement as frequently as practical, avoid over-feeding and keep up the aeration. ...And change water to get rid of the bad stuff.

                Comment


                • MikeM, you are very good at finding the story behind the story (if that makes sense). You have a rare skill.

                  Comment


                  • Originally posted by Jacques View Post
                    MikeM, you are very good at finding the story behind the story (if that makes sense). You have a rare skill.
                    I agree. Mike has that gift!

                    Comment


                    • Does anyone know how long unused sodium thiosulphate (ST) stays active in the pond?

                      For example, fresh source water with chlorine at 3 ppm requires a 10.5 ppm dose of ST. So the correct amount of ST is added to the pond based on the volume of fresh water that will be added. But what if work or something else interrupts the water change mid-way. Can I still come back the next day and continue adding fresh water while relying on the ST added to the pond the previous day?

                      Remember, only half the ST reacted with chlorine because I only added half the fresh water. So the other half of the ST dose is still in the pond - but is it still active?

                      Comment


                      • I don't have the answer. but glad to know you have info on how much ST to use. Do you have links to this info?

                        Comment


                        • Originally posted by Jacques View Post
                          Does anyone know how long unused sodium thiosulphate (ST) stays active in the pond?

                          For example, fresh source water with chlorine at 3 ppm requires a 10.5 ppm dose of ST. So the correct amount of ST is added to the pond based on the volume of fresh water that will be added. But what if work or something else interrupts the water change mid-way. Can I still come back the next day and continue adding fresh water while relying on the ST added to the pond the previous day?

                          Remember, only half the ST reacted with chlorine because I only added half the fresh water. So the other half of the ST dose is still in the pond - but is it still active?
                          If I am not mistaken you cannot overdose using ST.

                          Why take a chance?

                          Garfield.

                          Comment


                          • See post #25 on page 3 of this thread. Roddy Conrad posted very useful information on the use of Sodium Thiosulphate (ST) and its indirect toxicity to fish (a material overdose of ST leads to detectable levels of toxic Hydrogen Sulfide (HS)). More HS is formed at higher pH. Fortunately HS is very volatile and gasses off easily. But why take the chance if you can get the ST dose right? Note the ST was in concentrations of 50 or 60 times the recommended dose before HS toxicity was observed. Our aim should be to avoid even low levels of toxicity, so please do not find comfort in knowing that your Koi will only start dying when you get the ST dose wrong by a factor of 50 times!

                            Roddy's information was never challenged by the senior forum members participating in the thread discussion and was successfully benchmarked against recommendations by American Environmental Services Inc (US waste management company). I therefore accept his recommendations.

                            Be careful when looking at the recommendations by American Environmental Services. Chlorine reacts with waste in waste water, partially depleting the chlorine charge. Similarly, chlorine will naturally deplete to some extent in 'dirty' ponds requiring less ST to neutralize the residual chlorine. But then the objective is not to burn our fish while the chlorine sterilizes the pond! The point I am making is that a waste management company would arguably use less ST in their operations than what we would use in relatively 'clean' Koi ponds. Roddy's ratio is based on a pure chemical equation with zero 'system losses' and is hence higher.

                            So here some formulas based on Roddy Conrad's post:

                            Imperial:
                            Fresh water in US Gallon x Chlorine in fresh water expressed in ppm x 3.5 / 7490 = ST (in ounces) needed

                            For example, adding 3000 US Gallons of fresh water with chlorine concentration of 2ppm would need 2.80 ounces ST (3000 x 2ppm x 3.5 / 7490 = 2.80 ounces).


                            Metric:
                            Fresh water in kilo liters or m3 x Chlorine in fresh water expressed in ppm x 3.5 = ST (in grams) needed

                            For example, adding 10 000 liters of fresh water with chlorine concentration of 2ppm would need 70 grams ST (10kL x 2ppm x 3.5 = 70g).

                            PS:
                            The constant value of 3.5 used in the formulas is the ratio of ST to chlorine needed to neutralize the chlorine. So for every 1 ppm chlorine, 3.5 ppm ST is needed to balance the chemical equation (source: Roddy Conrad's post #25). American Environmental Services reportedly used a ratio of between 1.6 and 2.6 depending on pH. Change this constant if you want to dose ST using a different Chlorine:ST ratio.

                            Roddy Conrad then goes on and gives some very useful advice on the use and storage of ST (see post #26). I recommend reading this too. I would add the following:

                            • Ammonia is a byproduct of the reaction between ST and Chloramine. Check with your water utility on the use of Chloramine in your area and keep in mind the extra ammonia produced. Some use water changes to take on ammonia spikes after spawning.
                            • Only test source water for chlorine concentrations (ppm) after the water has been running for 10 - 15 minutes (maybe water the roses first ). I find that water sitting in the plumbing and supply lines have very little chlorine but that chlorine-rich water starts flowing once this 'old' water is purged from the system. I also find more chlorine in source water during times of high water usage in my area.


                            For some reason I feel the need for a disclaimer despite my pure intentions and double and tripple checking my formulas, so here goes: Use whatever you read here at your own risk.

                            Comment


                            • Originally posted by Jacques View Post
                              See post #25 on page 3 of this thread. Roddy Conrad posted very useful information on the use of Sodium Thiosulphate (ST) and its indirect toxicity to fish (a material overdose of ST leads to detectable levels of toxic Hydrogen Sulfide (HS)). More HS is formed at higher pH. Fortunately HS is very volatile and gasses off easily. But why take the chance if you can get the ST dose right? Note the ST was in concentrations of 50 or 60 times the recommended dose before HS toxicity was observed. Our aim should be to avoid even low levels of toxicity, so please do not find comfort in knowing that your Koi will only start dying when you get the ST dose wrong by a factor of 50 times!

                              Roddy's information was never challenged by the senior forum members participating in the thread discussion and was successfully benchmarked against recommendations by American Environmental Services Inc (US waste management company). I therefore accept his recommendations.

                              Be careful when looking at the recommendations by American Environmental Services. Chlorine reacts with waste in waste water, partially depleting the chlorine charge. Similarly, chlorine will naturally deplete to some extent in 'dirty' ponds requiring less ST to neutralize the residual chlorine. But then the objective is not to burn our fish while the chlorine sterilizes the pond! The point I am making is that a waste management company would arguably use less ST in their operations than what we would use in relatively 'clean' Koi ponds. Roddy's ratio is based on a pure chemical equation with zero 'system losses' and is hence higher.

                              So here some formulas based on Roddy Conrad's post:

                              Imperial:
                              Fresh water in US Gallon x Chlorine in fresh water expressed in ppm x 3.5 / 7490 = ST (in ounces) needed

                              For example, adding 3000 US Gallons of fresh water with chlorine concentration of 2ppm would need 2.80 ounces ST (3000 x 2ppm x 3.5 / 7490 = 2.80 ounces).


                              Metric:
                              Fresh water in kilo liters or m3 x Chlorine in fresh water expressed in ppm x 3.5 = ST (in grams) needed

                              For example, adding 10 000 liters of fresh water with chlorine concentration of 2ppm would need 70 grams ST (10kL x 2ppm x 3.5 = 70g).

                              PS:
                              The constant value of 3.5 used in the formulas is the ratio of ST to chlorine needed to neutralize the chlorine. So for every 1 ppm chlorine, 3.5 ppm ST is needed to balance the chemical equation (source: Roddy Conrad's post #25). American Environmental Services reportedly used a ratio of between 1.6 and 2.6 depending on pH. Change this constant if you want to dose ST using a different Chlorine:ST ratio.

                              Roddy Conrad then goes on and gives some very useful advice on the use and storage of ST (see post #26). I recommend reading this too. I would add the following:

                              • Ammonia is a byproduct of the reaction between ST and Chloramine. Check with your water utility on the use of Chloramine in your area and keep in mind the extra ammonia produced. Some use water changes to take on ammonia spikes after spawning.
                              • Only test source water for chlorine concentrations (ppm) after the water has been running for 10 - 15 minutes (maybe water the roses first ). I find that water sitting in the plumbing and supply lines have very little chlorine but that chlorine-rich water starts flowing once this 'old' water is purged from the system. I also find more chlorine in source water during times of high water usage in my area.


                              For some reason I feel the need for a disclaimer despite my pure intentions and double and tripple checking my formulas, so here goes: Use whatever you read here at your own risk.
                              Jacques, thank you for the explanation. Now I can get started on putting a Mazzei injector that will meter an ST solution into the water line sourced from our utility.

                              Will need to get the ppm of chlorine on our utility water, the flow rate of fresh water going into the pond, and the metering rate of the injector to find the concentration of ST I need.

                              Comment


                              • Originally posted by yerrag View Post
                                Jacques, thank you for the explanation. Now I can get started on putting a Mazzei injector that will meter an ST solution into the water line sourced from our utility.

                                Will need to get the ppm of chlorine on our utility water, the flow rate of fresh water going into the pond, and the metering rate of the injector to find the concentration of ST I need.
                                or you can simply throw 5 to 10 grams of ST crystal in the pond for every ton of new water. Its the same banana. In the koi show I just do that. I dont even measure weight.

                                Comment

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