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  • Weed

    Hi all..

    Just wanted to ask about the dreaded weed

    My pond is new built in Oct04 3,500 gals

    I have six fish in there at the mo biggest 12"

    i am not feeding them much at all at mo once a week

    I have taken pics of some weed in my pond

    most is growing along ther walls but i have been told that is not a problem and to not Hoover it off
    some though is floating on the surface

    the pond is not heated and water is very clear

    so what type of treatment should i start IF any at all

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  • #2

    it is not harmful as long as you have aeration, it reduces nutrient that has built up in the water.
    you can harvest some of it thereby removing some of the nutrient from the system.


    • #3

      Personally, I would physically remove as much as I could. It seems from those pics to be getting quite thick. I suspect you are just getting a long break-in period over the winter months, and that it will begin clearing on its own as the pond matures and temperatures rise. Since you are concerned about it, I'd suggest visiting a pond of a fellow koikeeper who uses the same water source and does not have an algae problem. Take a reading on the water parameters to compare to your water. Maybe something will stand out.


      • #4

        String algae (blanket weed) is often an indication of organic nutrient in the water (DOCs - Dissolved Organic Compounds).

        This algea can become very invasive. As Mike said, remove as much as you can.

        You say you are feeding a little. What temperature is your pond water? If too low for effective digestion by the koi, you may just be feeding the string algae.


        • #5

          Also read the thread called "blanketweed treatments" which ended on 12/29/04.

          With a title like this, I am surprised that Doug Ward, the Wakin King, has not reappeared.



          • #6

            I agree with Mike, the only solution is to remove what you can and first to make some water alnalysis to find what is wrong.
            My experience is very short, but I had the same problem when my pond was not deep enough. The temperature in summer was to hight, the algae develop fast and my koi did not eat a lot because the eat the algae... the only thing I was abble to do,before diging deeper, was to clean it and to cover the pond from the direct sunlight (less light for the algae and lower temperature of the water). Four days after my Koi were eating again.
            End of summer I dig my pond deeper, took a better filtration system and the next year I had no algae problem.
            Anyway, if the koi have enough oxygen, algae are very good for the colours.
            Good luck.


            • #7

              Is it true that when you remove this from the pond the spores that come off can all actualy make the problem worse???

              I have used Pond Ballance and this has worked well for me before.




              • #8

                Hi I keep my string algie down by putting barley bales in my waterfall. It works. Take a tolit bowl brush and stick it in the water and twiril it around and the string algie will cling to the brush and take a small bowl and put under the brush when you get ready to take it out of the water, if you dont it will just fall back into the pond.


                • #9

                  Arthur's right! You need to remove as much as possible because when the water warms it will take off, suffocating your surface skimmer, pipes, filters etc.

                  To me , to suggest barley straw will help the immediate problem ( thanks KFG)but it is not
                  addressing the cause. The way to fight organics is to set up a 24/7 trickle. Also have the water tested for phospates. Take a good look at your filter, clean it
                  and re introduce the right bugs with starter. Your bioload is not overwhelming but the number of times you put your pond thru the filter is in question as well as the efficiency of the filters. I used to run across this problem alot with over crowded ponds and with keepers who were so tight with a ha-penny that they only did water changes when they absolutely had to! That's why if your system does not have heavy phospates the trickle will clean it up.
                  Dick Benbow


                  • #10

                    There are endless solutions for string algae, none of which work all the time in all situations. I am going to contradict Dick, and someone else will contradict me. What works for some, does not work for others. One thing is for sure, if conditions are right, it will appear. It can not be excluded from the pond. You can only manage the pond in such a way as to prevent it from taking over. Here is my approach....

                    If left long enough, string algae will disappear on its own. When there is a build-up of the right type of lignin and other humic substances from decay processes the string algae growth is inhibited. The decaying barley straw is releasing lignin. Hence, the barky straw will sometimes (but not always) help. Personally, I would not use the straw and would rely on derivatives of compounds being released from the string algae itself. If you are trying to let the humic compounds build up, water exchange is actually counter-productive. I have had string algae flourish in a pond which received several hundred percent water exchange per week.

                    Having string algae is not as nice as having a clear pond with good water quality. However, it is better than green water and it is better than a clear pond with a lot dissolved nutrients which could stress the fish. If other components of your system cannot keep up, then string algae can actually be a benefit. String algae is something you can physically remove and when you throw out a big nasty green glob of string algae, you also throw out all the nutrients it has assimilated. What you are throwing out is essentially reprocessed fish food.

                    I will graciously accept the rebuttal.

                    -steve hopkins

                    Oh, and do try the cordless drill trick. Its very gratifying.


                    • #11

                      nah steve i reckon id go with that, ive used it as part of a filtration system before, id just harvest some of it off everynow and then.
                      i had a brilliant stocking rate going on in that tank, around five kilos of fish for 150 litre tank. they were happy as. you shoulda seen the food i could throw at it and theyd just bulk up unbelievably.
                      it just developed there in the full sun and i left it go because i figured it wasnt hurting the fish. if you dont harvest it gets too big. this particular tank had clean walls because the algae is living in the sun in a box and the tank is in the shade.
                      even my 5000 litre fibreglass conical tanks have algae all over the walls.
                      years ago id spend the time cleaning them with a brush or something, then clean out my filters for days.. now i dont even clean it off between fillings because i believe its part of my system now. i spose for some its too unsightly thats all, i could agree but havent the time to worry bout that anymore.
                      i can still see the fish well because the waters crystal clear, some even like a dark background for the koi to stand out on. im on the green is good team im afraid!
                      i thought it was a problem as the thing began to die off i got sad it didnt look so healthy, but i figured itd done a fine job anyways while it could and had to.


                      • #12

                        Hi Folks thanks for the replies

                        I have tested the water and the readings are as follows

                        ph 8

                        Nitrite between 0 -0-05

                        Oxygen between 12 - 15

                        Ammonia 0

                        Using the Yamitsu test kit

                        as befor the fish look happy water is not heated and have not fed them for about 3 weeks

                        Should i still scrap off as much from the pond walls at this time or leave it a while.

                        Many thanks



                        • #13

                          oxy is high, test it for yourself at 5am.


                          • #14

                            algae presence is indicative of the fact that it is finding a nutrient source, nitrate and phosphate, you could have low nitrite but thats becasue its being changed to nitrate and being available that way, so if your not going to change some management technique, like try extra water changes or whatever.. i would leave it there myelf, maybe just harvest some of it to keep it coming and not get overgrown. removing it all only, is not a solution to the problem.
                            in my mind i see it as the balance thats happening wants it there.
                            say you remove the sunlight its only taking away one of algaes needs and so the nutrient is still there..when thats the one you want to reduce for your fish.
                            i dont mind it if algae removes it for me thats all. if your worried about the look, think of ways to reduce nutrient load staying in the water. maybe grow an above water plant.


                            • #15

                              The normal pH is between 6.5 and 8.5, but the pH change often during the day, so you have to take it different time to have a good idea. If the pH is hight, the toxicity of ammonia increase too.

                              Ammonia should be under 0.02mg/litre, if it is too hight, the Koi will produce a mucus that you can see on the surface of the water.

                              Oxygen: the minimu is 6 mg/litre and maximum is 12 mg/litre

                              Nitrite: should be under 0.3mg/litre

                              Phosphate: It is the feed of the algae! difficult to judge because if 0.25 mg/litre is already enough to feed the algae, you can find 0mg/litre and have a lot algae in the pond because the algae have eaten all the phosphate ...

                              When I took my book to give you these values, I read that if you put 1.6mg/litre of salt, that will go agains the algae developement; I don't know if anybody already tried that...

                              If you intend to use barley, be careful to find some that had not receive any chimical treatement agains parasites ..., if not all the koi will die with the algae....


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