string Alga booming
  • huatyhuaty April 2011
    Posts: 69
    Hi all sifu, i noticed recently my pond wall fill up with string alga. Sometime they being suck into filter and jam up my filter. How to get rid of them? Please advice.
  • jayt49jayt49 April 2011
    Posts: 25
    hi bro huaty, i've read somewhere that says salt content of 0.5% can prevent string algae. maybe other bros here can comment?
  • PH8PH8 April 2011
    Posts: 683
    Salting, even if it works, is just a temporary solution. The minute the salt is gone, the string algae will come back. The best way to get rid of string algae is to deprive it of its food, which is nitrates, phosphates and sunlight. Nitrates and phosphates (which cannot be avoided since these are the byproducts of fish food and the nitrification process) can be reduced/kept in control by regular (daily) backflushing. Shading the pond will also help.
  • ta5851ta5851 April 2011
    Posts: 50
    Having the same problem. Just bought a set of pondovac 4 to try to solve this issue. The algae always suck into filter and jam up my filter, very troublesome.
  • ta5851ta5851 April 2011
    Posts: 50
    I think we know that barly straw can stop the grow of string algae. I think we also have alternative, we can use rice straw, it should work as well :) http://www.ncbi.nlm.nih.gov/pubmed/19256371
    http://www.iwtc.info/2007_pdf/1-6.pdf
    Post edited by ta5851 at 2011-04-06 07:37:37 pm
  • ta5851ta5851 April 2011
    Posts: 50
    but having one problem. have ask around and found out that the rice straw at my place full with insecticide, even the cow sometimes may die after eat it b-(
  • cookcpucookcpu April 2011
    Posts: 462
    I have google about using barly straw to counter string algae but from what I infer it does get rid of string algae and there is an after effect on your eco system of your pond.

    So I believe Bro Paul suggestion is the best solution. I have the same problem two month back and I do what Bro Paul suggested by back flushing daily.
  • huatyhuaty April 2011
    Posts: 69
    now i wonder, it is a challenge for solving this problem. My pond is 100% outdoor with direct sunlight from 12pm to 3pm.

    I was thinking to add in addtional UV light into pond directly since it help to control the alga but is there any side effect to the koi??? Will Koi blind???
  • PH8PH8 April 2011
    Posts: 683
    Bro Huaty, the UV lights are in the filter, the koi will never see the lights. No worries about blindness. But UV lights only kill unicellular floating algae, will not kill wall algae/string algae at all.

    Shading the pond would be good idea. I used to get algae bloom also, around this time of the year. Once I shaded my pond, never again. Shading the pond also helps reduce the water temperature, much more comfortable for the koi, their skin will be better and their appetite also improves.
    Post edited by PH8 at 2011-04-07 03:04:12 am
  • AndySittAndySitt April 2011
    Posts: 560
    Bros I truly agree.. Shade it... Even the transparent polyethylene that I used manage to get rid of all algae!!
    Post edited by AndySitt at 2011-04-07 06:48:59 am
  • AnuarAnuar April 2011
    Posts: 688
    Hi Bro Huaty, I tried salting and pp but did not work. I have heard some hobbyists suceeding with pp treatment. Right now the best solution for me is to scrub them off which can be easily done using those drain broom. I don't mind string algae, it is the floating ones that I cannot tahan, and they would normally get stuck at my water cascade. My pond is fully shaded using the nursery net but still receives about 30 pct of sunlight from a tangent angle for about 4 hours. I am also changing about 5 - 10 pct of water daily. I guess it would have been much worst without the water change and the shade.

    I also would like to relate that I recently left the pond unattended, I.e. No feeding for over two weeks and upon my return, the string algae situation significantly worsened. I had actually changed 30 pct of water prior to that. Must be the weather :-?. Or the pond had enough nitrates and phosphates to feed them even without fish wastes.

    Good luck.
  • PH8PH8 April 2011
    Posts: 683
    Bro Anuar, it can take many days for a fish to clear the digestive system. So that last feed would still be coming out while you're already outstation. Also, don't forget that koi eat algae too! That is food and will result in waste also. :)
  • st8800st8800 April 2011
    Posts: 103
    Yup.... the answer is shading the pond... once u do it... bye bye algae... may not even need UV later. Speaking from own experience too. Worth the investment if u are half serious about koi keeping.
    Best
    Spencer
  • cookcpucookcpu April 2011
    Posts: 462
    I wonder a pond with fast turn over help in keeping this algae away too.
  • ShukriShukri April 2011
    Posts: 4,881
    Nitrate management and no direct sunlight will ensure no or minimum algae.
    In Koianswers Forum, no one individual is above the rest. This is the Forum for the Koi Community.
  • ta5851ta5851 April 2011
    Posts: 50
    I think of diy a shade with pvc paip as frame and black net tomorrow. hopefully this will help me to solve the problems... :)
  • khongkhong October 2011
    Posts: 144
    Hi All the Sifus: Your advice and help is required.

    My pond is about 2 months old and I didn't had algae problem until last week. Now I can actually see quite some algae floating around and there are lots of it trapped in the sieve in Chamber #1. Actually, the surface of the sieve is fully covered by the algae in green color, and I can feel the weight of it, compare to when the sieve is cleaned. (should be dark green, I guess)

    My pond is not shaded and it is under sunlight for about 4 hours in a day. I have UV light in my pond chamber since day 1 and the UV light is always ON. Prior to last week, I didn't see algae trapped in the sieve. I did back flush every alternate day with about 5% water change. In addition, I added the "biozyme" on weekly basis to help to control the algae, since the pond is filled with koi.

    Since all of sudden there is an algae attack, could it be something else not right with my pond?

    Other than shading the pond, is there anything I can do?

    Thank you.
  • PH8PH8 October 2011
    Posts: 683
    How big is your pond and how many fish inside, roughly what size? You could start by trying to backflush daily instead of every alternate day. This would help lower nitrates. Shading is still the best though.
  • ashfaqashfaq October 2011
    Posts: 799
    Brother Paul,
    Can we introduce 1 or 2 Grass Carp, so that it will eat algae?
    Thanks,
    Ashfaq from India-Chennai
  • PH8PH8 October 2011
    Posts: 683
    I don't know the definitive answer, but here is a link... http://www.maggotdrowning.com/fish/grass_carp.htm

    Seems like a grass carp can eat up to its own body weight in one day. So quite likely your pond may get less and less algae but your koi will become more and more skinny...
  • khongkhong October 2011
    Posts: 144
    hi Paul: My main pond is about 13' * 11' and the filtering chamber is about 12' * 3' and I only have 10 kois which 3 of them are 30+cm, 2 are about 40c+m and the other 5 are around 20+cm.
  • PH8PH8 October 2011
    Posts: 683
    Do you know how many tons? I can't calculate since you didn't provide the depth. You need to know your water volume for medication purposes. Anyway mostly small fish so even if your pond is only 10 tons, you aren't heavily stocked, for now anyway. Try backflushing daily, see if it helps.

    Ps. Assuming your depth is 3 feet, your pond volume is roughly 15 tons. Next time you salt your pond, calculate your pond volume based on the formula that 1kg of salt raises salt level of 1 ton of water by 0.1%. Believe you should have been salting your pond during the 1st 2 months, right?
  • ikankoikauikankoikau October 2011
    Posts: 1,053
    Bro Khong,
    Just to add in. You must identify whether it's single cell algea or string algea. UV light is effective in solving single sell algea which responsible causing green water. String algea is due to excessive Nitrate AND sunlight. You have to kill either one or both for better result. Lately it was so hot which might have cause algea bloom to some ponds. It started by blooming at wall and floor's surface and detached and floated when it became too long or got disturbed by the kois/water activity.

    The floating string algea can be removed by filtration/sleeve or you net it but it will take some time.Try to cover your pond esp during hot weather or carry out more water change. In worst case, scrape the string algea on the wall while holding a net under/beside it and make 30 to 50% water change. This will be a quick fix. By doing this, you will reduce the nitrate significantly. The water will be clouded for a few hours but it will get better. Then clean your first chamber.
  • khongkhong October 2011
    Posts: 144
    Hi Paul: you are right, the pond depth is about 3.5 feet and the water level is at 3 feet. I salt my pond twice since I started the pond and the last time was about a month ago. Then I forgot about salting the pond. Do I need to constantly maintain the pond at certain salt level?

    This morning I back flushed the chamber #1, and also #2 which is filled with J-matt, (I also cleaned the J-matt) with about 20% water changed, I added in the biozyme and 10kg of salt. Let's see how it goes.

    Bro Captain: I think my pond should be "attacked" string algae as I can see it is quite long and it grows on the wall. This morning I scraped some from the wall.

    Thanks for your advice.
  • PH8PH8 October 2011
    Posts: 683
    Bro Khong, the reason for salting start up ponds is to protect the koi against nitrite spikes before the good bacteria colony has been formed. It normally takes about 6 weeks to stabilize enough to take care of ammonia and nitrites. So perhaps yours is already OK, but best if you could just check your ammonia and nitrite levels. If they are OK, then no more need to salt the pond. Do you have a digital salt meter? How much did 10kg of salt raise your salinity by?
  • khongkhong October 2011
    Posts: 144
    Unfortunately I don't have a digital salt meter, I assume that 10kg of salt will rise less than 0.1 of the salinity level.

    Obviously it is not good to have "ass between u & me" (asss-u-me) :-D Just kidding, hope you don't mind.
  • huatyhuaty October 2011
    Posts: 69
    Khong, just wanna share my painful experience that i lost 3 lovely koi due to this problem. By feeding less and apply algacide, it work but only solved temporarily. Due am no feeding them, my koi start feel hungry and eating/grasp string alga and those un-consume floating alga flow into filter then stuck at sleeve, water unable flow thru causing pump chamber lack of water........meaning, my entire pond water fall is not running causing water low oxygen. This kill my koi when am outing for 2 days only.

    This is solution i applied and it solved now, completely remove fish and clean up entire pond, this included the filter matt as well. The recondition water pond now is now under control by continuously water changing with some %(more this time). Feeding less and, flush chamber weekly. It entering 3 mths now and still works, pond still without shading & pond wall is start cover up with surface alga. But my koi clean it off due to am under feeding them 50% compare previously.

    Conclusion is when alga had alry start booming and out control, no other solution can help unless completely remove them. Shading pond/apply medicine will not remove what alry happened inside pond but it slower down growing rates. Hope it can help you. thx



  • kominatokominato October 2011
    Posts: 408
    Do you have direct sunlight on the pond?
  • PH8PH8 October 2011
    Posts: 683
    No worries with jokes, bro Khong. :-D But do try get a digital salt meter. It is not very costly and will help when you need to salt your pond later to different levels. It will also help you to assess your pond volume more accurately, and you will definitely need to know your pond volume when you medicate your pond. If you overdose, fish can die. If you underdose, maybe no effect.

    Bro Huaty, if you feed only 50% now, then maybe all your koi will look very skinny. I know many koi kichi don't like skinny kois. Maybe the solution to keep nitrates down is to backflush daily and provide shade instead of feeding only 50% and backflushing once weekly. Anyway it depends on what you want.

    There are many forms of shading, direct and indirect, and many different materials available from canvas to timber to polycarbonates. Maybe one of the forms might be nice looking and acceptable....to the Home Minister especially. :)
    Post edited by PH8 at 2011-10-03 05:56:01 am
  • raymond_ongraymond_ong October 2011
    Posts: 90
    Bro Khong, i think Bro Paul is right, having a salt meter is very important. It's easy to get your salinity level right when your pond is 0% salt, well just put 1kg per ton, you'll get 0.1%. Problem is when you start to dilute your water such as back flush and from rain water, then you don't have a clue the status of your salinity level is.

    By the way, you can get a reliable digital salt meter costing around RM200 plus.

    Bro Huaty, thought you covered your pond already?
    Post edited by raymond_ong at 2011-10-03 07:47:52 am
  • khongkhong October 2011
    Posts: 144
    Hi All,

    Not sure if my kois are eating algae but it appears like lthey are eating slower compare to 2 weeks ago. Though I am still feeding the same amount of food, but sometime they just couldn't finish it.

    I also suspect it might cause the change of koi food. Since 7 days ago I started to feed Marubeni Super high growth, which is sinking type. I only feed the sinking food once a day and the rest of the meals is still with the floating wheatgem. However, it seems like the kois are confused on where to look food - surface or bottom?

    Did anyone of you have similar experience?
  • PH8PH8 October 2011
    Posts: 683
    No koi won't be confused where the food are. In the wild, food can be anywhere, and there is hardly any visibility. They will know. :)
  • huatyhuaty October 2011
    Posts: 69
    marubeni is good, my koi loving it but it tend to create sinking/parking disease if consume more. am now using hikari growth sinking and sakai color with 70/30 ratio it look fine.

    PH, My koi doesn't look skinny, they all fat fat maybe previously am over feed them causing nitrate spike/alga booming and now cut 50% maybe the right ratio. Was thinking to shade the pond too but just hav no idea how to design it nicely. Question is even cover it with root but sunlight still able to enter thru side way right. FYI, my pond got 2 hrs direct sunlight rest is cover up by the building when sun moving.

    Khong, separate single feed to multiple feed with the same amount is recommended as previously my koi cant finish up the food too. but with multiple feed, they all more reactive to me everytime am feeding and they clear it all. :)
  • khongkhong October 2011
    Posts: 144
    Hi All,

    I really not sure what happened to my pond. Since I washed my filtering chamber on Oct 3rd, i did back flush everyday. And I can see that the algae collected by the sieve is lesser and lesser. Actually, there was no algae at all when I wash the sieve last night at about 10pm and I was so happy.

    However, I was very surprise this evening to see so much of algae collected by the sieve, and it is really a lot. Just imagine 2 pieces if sieve full of algae! In addition, I can see the algae floating in my main pond. How can thing chanegd so fast, within less than 24 hours?

    2 hours ago I back flush chamber #1 & #2, really not sure what to exoect in the coming days.

    Any opinion and advice will be much appreciated.
  • khongkhong October 2011
    Posts: 144
    To add a bit more, I stop feeding the koi since Tuesday. Shall I continue feeding? By the way, the koi seems like not having too much of appetite to eat.

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