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no filter in a livebearer breeding tank?

Home Forums My Aquarium no filter in a livebearer breeding tank?

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    Dear all,

    Has anyone tried the following: a breeding set-up for livebearers with some aeration, but without any filter. In stead, several times/weekly siphoning of all debris and at the same time changing a part of the water. In addition, some kind of background consisting of a pile of hardwood (beech) branches which will – no doupt – have a healthy bacterial growth for biological filtration, and which function as shelter for small fish?

    Would this potentially work? I wonder about this, because in a typical filter a lot of fish-poo piles up and is then removed only every now and then. So in an aquarium with filter, much of the time a lot of fish-poo is present, only invisibly in the filter. In the set-up I have in mind, all will be visible and removed instantly …

    The inspiration for this idea comes from a text on the Bristol aquarists’ website where someone has two ponds for golden orfe, which he uses alternately and routinely cleans/desinfects. His stocking density is extremely high, yet the fish in his ponds look very healthy on the photograph. Basically he manages his fish like other breeders manage small birds/mammals …




    You could also consider a ‘best of both worlds’ approach: install a polyurethane foam block to create a separate compartment in the tank, add an airlift pipe through the PU foam and voila: you will have stable biological filtration, with only little current, so larger particles (uneaten food/faeces) will remain on the tank floor to be siphoned out.
    The addition of sufficient surface area that can be colonized by bacteria will provide more stable water quality and even have an effect on the structure of the bacterial community in the aquarium, which should give some protection against opportunistic pathogens.



    I have often seen such tanks and I know this aproach can function very well, yet i am wondering if it is possible to go one step further … Perhaps (many) moss-overgrown branches can do the same?



    Don’t think this is a step further, rather backwards. Filters have been invented and are used for a reason. Your branches will never reach the surface area an internal filter normally has.

    However, your approach can work and I have seen it done by professional fish breaders. Water exchange was about 90% at least once weekly.



    Last month we had a speaker at our aquarist club who is reknowned for his experience with plants and general aquatic biology. He goes much further and actually takes your question to the limit. His name: Albert Sanderse.

    He runs a breeding tank of 150x50x50 cm, planted with nothing but plastic plants, no filters whatsoever, moderate lighting (plastic plants do not require any). Monthly (!) water changes of 10-15%, at which moments he removes depostis gathered on the gravel 2-3 mm). One every quarter year he infuses his aquarium with fresh bacteria he obtains from the smelly water in the vases that hold the flowers (Chrysanthemums) he gives his wife. Fish (tetras, barbs, labyrinths and small cichlids) breed like crazy, but he is mostly letting the young fight for themselves as he is past reproductive years (83).

    His secret: moving water! He uses only air outlets (the bubble kind) to have a) sufficient warer surface movement and b) general flowing water throughout his tank.

    The reason: in nature it is not the plants providing our fish with O2, but it is the exchange of gasses through the (moving) water surface. It works for the O2 for our fishes, but the plants will have sufficient CO2 for their (normal) daytime assymilation and enough O2 for their nighttime dissimilation (growth).

    The added bacteria will break down anything the fish “produce” and have enough O2 at hand to do so. Very important remark he made: NO huge water changes, as this breaks down general resistance of your fish.

    Same tactic works in a planted aquarium as well. He has a cabinet full of national prizes to prove it.

    I recently have incorporated his “moving water” theory into both my aquarium and plant filter. Immediate effect on the fishes: not hanging just below the water surface at dawn where most of the O2 can be found after the plants have been dissimilating all night,… but they now sleep at their “normal” water depth.

    It is too soon to draw any other conclusions of my own. And it is far too early to get any effects of the bacteria infusion as the Chrysanthemums only died yesterday….


    Graham Ramsay

    Good circulation is advisable in any tank. Filter or not.



    I would be very carefull with Chrysanthemum, as they contain chemical substances which are commonly used as very powerfull pesticides. Berhaps they are broken down in “rotting water” but I’d bring some other flowers for the occasion (bulbs are also suspect … no lilies or tulips).



    The pyrethrins are only contained within the fruits, so the use of that water may be OK (although it’s possible cut flowers are treated with other nasties during importation to get rid of potential pests).
    The thing to consider is, that particular approach may work for one person who sticks rigidly to a routine, but could very easily be a disaster for others. What he’s doing is using the whole aquarium as a filter, but as has been said, a Hamburg Mat-style filter willl do this far more efficiently and reliably.

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