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Pea Green Water

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  • Pea Green Water

    Pea green water in the mud pond is good. In our closed concrete ponds, the same is not so!

    pH swing, visibility and change in oxygen content of day and night .... are some of the undesireable traits to keep pea green water in a closed pond. But why it is OK with the mud ponds? Donald
  • #2

    Its good in a mud pond for the same reason its good in any pond, it is favoured by the fish, it is more healthy for them in the nutrients etc in the water and also for colour I believe. Others will explain better the science behind it Im sure. The only reason we dont have our ponds green is for our own benefits, so we can see the fish better, its less healthy for the fish though.

    I have allowed my pond to go green in the past for periods of time and havent suffered with any of the problems you mentioned appart from a bit of extra mechanical filter maintenance for a few weeks when I switched the UV back on.


    • #3

      [email protected], how can pea green water good for koi?

      pH swing = would stress them for constant adjustment.

      Visibility (poor) = prevent early illness intervention.

      Oxygen content = Oxygen depletion can kill in early wee hour during summer.

      The only benefit of pea green water is to calm down shy koi in a small pond. And there are many ways to calm a shy one down. Donald


      • #4

        It is a stocking density thing. The ph swing won't happen in a properly stocked mud pond because of the stocking density. A ph crash might, but the swing will be very slow because of the huge mass of water. Ditto for temp swings and O2 depletion.

        Visibility issues are a GOOD thing in a mud pond too. Makes it difficult for preditors.


        • #5

          Jason, many was the night when the gang was up after working all day as properly stocked tosai ponds in hiroshima got dumped hard with acid rain.
          The alarm monitors would go off every little bit thru out the nite and a ph adjustment agent would have to be quickly dispensed. There are lots of other factors affecting Ph than properly stocked ponds. Quess who had to keep working the next day after 24 straight. something about feeding the koi.and maintenance..(lol) Sounds glorious but mud ponds are a lot of work!
          Dick Benbow


          • #6

            You will get a variety of views on green water. If it is opaque ... truly like pea soup, I think that is too risky, whether the pond is concrete or mud. Oxygen depletion is as serious a concern as the other factors you mention. However, a greenish shade is not as negative, in my opinion, as some others think. The unicellular algae are very efficient consumers of ammonia. Their presence forms a cushion against nitrogeneous wastes in the water, and in the process skin is protected from irritation and colors are enhanced as a result of not being exposed to nitrates. That said, forget any notion you might have of trying to cultivate green water. It is humanly impossible to create favorable conditions that are not at risk of getting out of control to the detriment of the fish. The one exception is the cultivation of green water in fry ponds for purposes of feeding the fry. It is larger fish that are most at risk. Fry thrive with the micro life to consume all around them.


            • #7

              Mike, the slight tint of (algae) green is the most ideal condition for water and gosanke. The water clarity is clear enough for viewing but the algae are there in number to benefit the koi's skin quality and the beni. I have seen a ZNA judge's pond with the above water conditions, and the sheen and luster are out of this world. And the beni is so red that it hurt my eyes. Some days I would acquire a similar skill to keep water like that .... for now, my pond need more seasons to reach maturity. Donald


              • #8

                green water versus clear water

                During the day, the single cell algae in green water consume carbon dioxide for photosynthesis, produce oxygen as a photosynthesis byproduct, while simultaneously consuming oxygen for respiration and releasing carbon dioxide through respiration. The net effect during the day is to consume carbon dioxide and produce oxygen. During the night, there is no photosynthesis going on so no carbon dioxide is consumed and no oxygen is produced, but oxygen is still being consumed through respiration and carbon dioxide is still being released through respiration. Obviously, there is a net loss of oxygen and net increase in carbon dioxide at night.

                In a static mud pond, the effects of green water are oxygen, carbon dioxide and pH diurnal cycles. After spending most of the day photosynthesizing, the oxygen level is very high - saturation or above. The carbon dioxide level is very low. The removal of carbon dioxide (a weak acid) causes the pH to rise. At night when photosynthesis shuts down, oxygen is still being consumed and carbon is still being produced through respiration. So, the oxygen and pH increases all day and declines all night while the carbon dioxide declines all day and increases all night.

                What usually kills fish first in a green water pond is night time oxygen depletion. This usually occurs when there are days of bright sunshine followed by a few days of heavy cloud cover. The days of bright sun allows the algae population to rise. The more algae cells there are, the more oxygen is produced during the day and the more oxygen is consumed at night. If there is a very high algae cell density and the weather turns cloudy, then the algae are not able to produce as much oxygen through photosynthesis during the day, but they still consume the same amount of oxygen through respiration. By dawn, the oxygen which was produced by photosynthesis the day before may be depleted and the fish are gasping at the surface or dead. There is another phenomenon where a heavy rain can "turn over" a static pond and cause dissolved oxygen depletion but we will leave that for another time.

                In a heavily aerated green water pond, the cycles are muted and the dangers are much reduced or eliminated. Aeration allows oxygen to reach saturation during the day, but aeration can actually remove oxygen if the pond would otherwise be slightly supersaturated. Daytime aeration also replenishes some of the carbon dioxide which is being consumed through photosynthesis. At night, aeration replenishes the oxygen being depleted by respiration and drives off excess carbon dioxide being produced by respiration. There will still be oxygen and carbon dioxide cycles, but they will not be dangerous if the amount of aeration is properly sized for the pond volume and bio-load.

                The primary benefit of green water is the food chain that develops because of it. The single cell algae are consumed by many micro- and macro-organisms. The micro-bugs may be consumed by crustaceans and other larger forms. Some of these larger forms are consumed by koi. In fact, carp in general are very efficient at harvesting the biomass one or two steps up the food chain from green water. This natural forage can seem almost magical as it allows fish to grow rapidly and develop a very healthy appearance. It is the perfect diet which we try to emulate with our prepared foods. The benefits of the natural diet out-weight any negative effects associated with diurnal water quality cycles.

                However, this natural feeding process and the availability of koi forage is highly controlled by fish density. If there are too many fish, the population of larger forms of forage creatures never has a chance to develop properly because the grazing pressure is too high. We can use supplemental feed (out of a bag) to increase the availability of stuff to eat and allow a modest increase in fish density without sacrificing growth. However, when the line is crossed and the natural forage is being over-grazed, that growth-enhancement effect is lost and the fish derive little benefit from the green water environment. You can see the same thing happen with range-fed chickens.

                This, I feel, is the basis for our preference for green water mud ponds where the fish density is very low, and clear-water concrete ponds where the fish density is very high.

                -steve hopkins


                • #9

                  Steve: For koi over 20", I would think the natural food is more than a few steps up the chain, although I recognize that a huge volume of micro life can be filtered from the surface inch or so of mud bottoms.


                  • #10

                    BTW, excellent post.


                    • #11

                      Agree, Steve knows the science and willing to spend the time! The art would come with time .... a hopeful future JR jr here!! Despite of his knowledge I notice that Steve still asks a lot of straight questions all over the cyber. A mind that is still at the tategoi stage! Scary! Donald


                      • #12

                        JR Jr.!! Which one of us are you trying to infuriate Donald?

                        Oh, I forgot; we are polite here. In a more serious tone, I will say that I came to koi several decades too late to ever reach the level of my hero James. With practice, I hope to develop just as sharp a tongue though.



                        • #13

                          Oh my! Steve, even the writing style and the sarcasmos match! What is a coincidence! Donald


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