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The pond cycle and how it relates to clean outs

Discussion in 'Water Features' started by jp14, Feb 19, 2011.


How did you develop your spring cleaning/maintenance methodology and procedures?

  1. Trial and error

    0 vote(s)
  2. Using procedures learned from another contractor

    1 vote(s)
  3. Taught my current procedures at a pond seminar/certification program

    0 vote(s)
  4. The result of independent research and education

    2 vote(s)
  5. Hired by a customer to perform specific cleaning operations

    0 vote(s)
  1. jp14

    jp14 LawnSite Member
    Messages: 24

    There was another thread on here about spring clean outs and it got me thinking about a related subject. When a new pond/water garden is installed, we all know that it takes a certain time period for the biological component of the filtration system to get up and running. So we let the system run, maybe add some bacteria or even water from another healthy well balanced pond and wait patiently until adding goldfish or koi. Once the filtration system can safely handle a fish load, then fish are gradually introduced.

    Now if we accept this as standard practice and the "correct" way of doing things, let me pose this question: How does a spring cleaning service that entails a total drain, pressure washing, scrubdown and refilling with fresh tap water differ from a pond that was just built? In the case of the spring cleaning job, we house the fish temporarily while we do the cleaning work and then put them back in the pond when we are done.

    Let me be clear here that I am not making any judgements on how each contractor works or the methods he follows. I am more interested in starting a discussion about whether or not we can improve our methods and make them more consistent from start (install) to finish (recurring maintenance). So how can we tell a customer that they must wait a set time period before adding fish when the pond was new but it is perfectly fine to drain and refill their pond in spring and chuck the fish back in right away?

    Perhaps this discussion is more relevant to those of us that work in cold weather climates that require the dreaded "drain & dump" cleaning technique. Again, without getting sidetracked and moving this thread into the realm of what is right and wrong with installations being done, I just want to talk about what is the best way to handle the jobs that have already been installed. So if a pond requires a total drain, cleaning and restart then how can we explain/justify/support the notion that the fish can be put back in immediately?

    Are we off track on the need for an initial start up period? Do we believe that starter bacteria and other additives make the pond safe right from the start? Maybe we hope that enough dormant bacteria survived the winter and the thorough spring cleaning process and it will quickly activate and make the pond safe for fish? This then leads me to another question.

    Is there a difference between a drain/clean situation and a pond that goes through winter (again assuming a cold weather climate) and experiences a period of dormancy in which the bacteria are performing little or no bio filtration? Will the fish experience a different set of stressors in a dormant pond waking up and starting anew in the spring as compared to the same pond being drained and cleaned and started back up with fresh tap? What role does bio film and anaerobic (working on the assumption that most of the aerobic bacteria was dormant) bacteria play in making the undisturbed pond better or worse for the fish during the spring "wake up" period?

    I would like to hear everyone's thoughts and opinions on this subject. And for those guys that work in warmer climates where this problem may not exist, is there some other cleaning related issue you have to deal with that doesn't affect us cold weather guys?
  2. tadpole

    tadpole LawnSite Bronze Member
    Messages: 1,221

    Even though I am in the South, occasionally I am required to preform a complete clean-out on ponds that are poorly maintained or were improperly installed by someone else.
    i utilize two (2) 500 gallon portable holding tanks that I fill with the existing pre-cleaning pond water. The fish are housed in these tanks until the cleaning is completed. It is then returned to the pond first, with the fish, and the pond is topped off with tap water. In my geographical location this provides the seed bacteria and other microorganisms which help in returning the water to it's original precleaning state. It also moderates any possible abrupt sizeable changes in temperature and pH which can prove stressful to fish.
    If I am dealing with large Koi (10"-12" and larger), I sedate the Koi prior to transfer and keep them sedated until they are returned to the pond. Enables easier netting and greatly reduces stress levels in the fish.

    I also do not pressure wash, I vacuum. This has proved to be less disruptive to the established biofilm.
  3. eastcoastjessee

    eastcoastjessee LawnSite Member
    Messages: 64

    I was thinking of using our 700 gallon water truck to pump pond water into when doing pond clean-outs and using a 250 gallon holding tank for the fish. To me that seemed to be the best logical solution for providing beneficial bacteria and nutrients immediately into the pond but I wasn't sure.

    Can you tell me a little more about the Koi sedation as it pertains to this topic?
  4. jp14

    jp14 LawnSite Member
    Messages: 24

    I also use a holding tank when doing cleanouts. However I am curious on your opinions about the relationship between bacteria content in the water and in the filter. I know there is some "free" bacteria present in the water but it is my understanding the bulk of the bacteria is present in the filter media or on the "bio film" that coats the pond surfaces. If a total drain is required and even if you don't pressure wash (another thing I shy away from), that still creates a condition (in my opinion) where most of the bio film is destroyed and the filter bacteria are essentially wiped out unless you can keep the media in an oxygenated environment the entire time. In my experiences with ponds that need total clean outs, the filter and/or media are usually so dirty that they require a thorough cleaning which is extremely disruptive to say the least in regards to the bacteria colonies. So in a pond of 1000 gallons, saving 1/2 the volume and returning it to the pond would clearly help jump start things but in a pond of 4000 gallons, how quickly would the benefit of returning a 1/4 of the water be evident? Finally, even if we could return 100% of the water after the cleanout, would we still be basically starting from scratch if the filter had to be cleaned, including the media?
  5. tadpole

    tadpole LawnSite Bronze Member
    Messages: 1,221

    The product used for sedating the Koi is called "Tranquil". One 8 oz. bottle treats 750 gallons. It is used by the hatcheries as a stress reducer when shipping Koi. I get it from Aquatic Eco-Systems, Inc. in S. Florida. I am sure that you can find it closer. It is manufactured primarily to be used in Live Bait wells. It works so well that you can pick up the Koi by hand, though not recommended. I was evidently the first one to use it for sedating Koi during pond cleanings according to the chemist at the manufacturer. I had called questioning the safety of it's use. He had never heard of it being used for this purpose so could really give me any advice. It requires some on-site volume calculations, because an overdose can quickly kill a fish. I have had great results with it's use. It is a real time-saver in reducing netting and transfer time which results in a great reduction of stress on the fish.
  6. jp14

    jp14 LawnSite Member
    Messages: 24

    This thread has got me thinking about making changes to my clean out process, perhaps trying to store and reuse as much water as possible (but still doing 10-20% water change). I would enjoy looking into the source Tad referred to about biofilm and how hardy it is. In many of my total cleans, I scrub and wash most of the pond surfaces and the pond may be dry for a few hours so I would like to do more research on time/moisture conditions and how that affects the loss of biofilm. On the subject of lava rock, in the ponds I work on I have found that due to the dormant state of bacteria through the winter months the lava rock is so thoroughly coated/clogged with muck/debris/silt that nothing short of a high pressure cleaning will do the trick. Ribbon media is much easier to clean and I can usually just throw it in the pond and "wash" it in there before I drain the pond.
  7. STL Ponds and Waterfalls

    STL Ponds and Waterfalls LawnSite Bronze Member
    Messages: 1,174

    Do you any for the customers.:laugh:

    Seriously how long before the Koi start getting back to normal after a sedation?
  8. tadpole

    tadpole LawnSite Bronze Member
    Messages: 1,221

    Just the fact that I don't have to chase koi with a net and possibly causing physical injury to them in the process keeps me a hell of a lot calmer.

    This Tranquil stuff is pretty amazing. It takes effect in only a few minutes and the fish recover just as fast.
  9. tadpole

    tadpole LawnSite Bronze Member
    Messages: 1,221

    There is quite a bit of info on the internet concerning biofilm. Only recently have they really began to dig deeper into it, research-wise. Dental assistants know all about it. Plaque is a biofilm and we all know how tough that it!

    Is there a reason that the filter media can't be cleaned prior to ice-over? Like maybe in late Fall?
  10. jp14

    jp14 LawnSite Member
    Messages: 24


    Listed above is some good reading. Do any of you guys keep a "supply" of media ready for your next install? Perhaps housing enough media for a few installs in a display pond that you can then take when you do an install and get things up and running much quicker? Or maybe keeping a pond full of stones, gravel, rock, etc... that you can then incorporate into a build so that you will have biofilm present from the very beginning? Some very interesting statements in these articles, especially in relation to the notion that biofilm represents the bulk of the bacteria in the pond system and that not all biofilm residents are beneficial.

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