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Co2 diffusion

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    can you guys suggest the cheapest way and or easiest way to add co2 to my tank

    i have heard that you can make a reactor to add by using yeast and water in a bottle

    has anyone used or tried this method?

    my plants are simply not surviving even though i feed them once every 2 weeks

    or is this not enough

    ive only got 7 plants in my tank

    im trying to grow them simply for colour as the fish are quite destructive






    you can make a reactor with yeast or buy a commercial version. Only problem with these are that they aren’t very consistent in deleivering CO2. This can lead to algae problems, as algae loves a CO2 imbalance.


    If you’ve only got 7 plants and low lighting levels then i’m not sure you’ll need to add CO2.


    What are your tank parameters, lighting levels and fert regime. Also what fish and plants do you have. It is likely to be something else rather than CO2.



    thanks for replying BD

    tank volume is 435 litres

    parameters are all okay with the exception of ph its currently sitting at 7.6

    lighting for my tank is 2x 45″ t5s with reflectors

    ferts as per bottle instructions which say to dose fortnightly (this is just a pet store fert)

    fish: 4x geophagus altifrons

          3x severums

          quite a few smaller fishes none of which are plant eaters corys, loaches, ancistrus and tetras for upper levels

    the 3 sevs do tend to pull at the plants but ive tried to find plants that they wont eat

    java fern,amazon swords and anubia being the chosen ones but they are not doing well at all

    i know anubia is a real slow grower but i heard that java fern goes like crazy

    the leaves on mine are browning and dying off all except anubia

    i would put a lot more plants in if i thought i could keep them alive

    lighting in mind could be an issue but the tank cover i have doesnt really let me put in more

    lights as the space is quite small

    ive also done away with the condensation trays to allow more light to flood the tank

    i dont mind adding a little water now and again


    i hope all this can help you to help me


    thx bud 🙂




    More questions mate!


    How long do you have the lights on for?


    whats your substrate? Have you ever added root tabs to the substrate, what about iron.

    Amazon swords are greedy root feeders and prefer a lot of iron.


    Anubias grows in very low light conditions – i have soem in a tank wich hasn’t had the lights on for a bout 6 months (no fish in it!) and it’s still growing!


    Java fern should also grow in low light conditions. Any pics?



    lights on for 12 hours

    substrate fine gravel

    no to root tabs and iron

    anubias are to back of tank

    the java fern was much larger than it is now  just dying off



    Java fern dont like their roots being planted – they do much better tied to a rock or log



    thx colin

    ill sort that this weekend




    @Bluedave said:

    whats your substrate? Have you ever added root tabs to the substrate, what about iron.


    Amazon swords are greedy root feeders and prefer a lot of iron.


    Adding root tabs for the Echi’s would also be my first step to revive them. Doublecheck to make sure the tabs come with macro and mikro fert’s. I personally keep them in little cups with very fine sand (the fert’s stay in there).

    good luck



    thanks thats sounds like a plan





    Looks like you have left the plants in the pots you bought them in with the rockwool still attached? Thats probably your main problem as it stifles root growth. Take them out and remove as much rockwool as possible.


    Whip the Java fern out and tie it to that lovely bit of wood behind – it’ll soon bounce back.


    Anubias is the same, they like to be tied to rocks and wood, however, you can plant it in the gravel but you have to make sure the rhizome (the long bit with all the roots coming off it) is out of the substrate. hopefully you can see what i mean in the pic below:




    If your fish keep digging them up you may want to tie them to a small stone (to act as an anchor) and place on your substrate, the plant will soon send roots into the substrate and hide the stone.


    Wasserscheu’s suggestion of little cups with fine sand and a fert tab is a good one, however, this will restrict the growth of the swords – they have massive root balls. Might be a good idea to establish them and then plant them directly when they have put on some growth? They should be ok in the gravel (out of the rockwool) with some fert tabs close by. I always use a layer of laterite in tanks that contain Ech. species (although adding that to your substrate with water in may prove troublesome!).


    Hope all that helps!




    Wasserscheu’s suggestion of little cups with fine sand and a fert tab is a good one, however, this will restrict the growth of the swords …

    Of course you are absolutely right Bluedave, by application of common sense and thinking of a natural environment. But in an artificial setup, we need to go off-nature thinking occasionally, because we are simply not capable to copy nature’s proportions in such a small place. By applying the right amount of the right nutrition directly to the roots, the plant does not need massive roots anymore, in the 2nd pic you can see the rootball fit’s in my hand (cup volume = 0,25 litre or 8.5 US Fluid Ounces):



    here (towards the left) a large Echi together with a bunch of Crypto’s in a pudding cup (also fits into one hand), in my “research tank”:



    That’s what a rootball looks like, after taking out of the cup and rinsing off the sand:




    I do admit though, that some Echis (like the hybrid “Frans Stoffels” for example) builds even “little potato-like” balls to store nutrition, and sends its roots far to explore nutrition sources. There are ways to “shortcut” this. It gives even the opportunity to regulate the size of the plant, by its amount of nutrition provided and cup size.

    I have done endless trials over years with all kinds of fert’s and someday should write a proper article with detailed instructions its results and photos.

    My conclusion for my large tanks (for my personal needs):

    no ferts in the water (except CO2 in some tanks, and that only to avoid biological decalciphication [plants breaking up calcium to get the Carbon of it, that leaves an ugly sandy layer on the leaves]) – only rood feeding.

    Other plants like moss still grow well and pure leave feeders need to hunger – there’s always a compromise, unfortunately. However, it is amazing how many plants I have managed to switch to rootfeeding only.

    In case of really starved out plants, I’d add liquid fert. into very fine sand, as first aid, but I don’t recommend that in this case, as there are too many details to consider – one option would still be ok, to inject good fert. that is sold for pouring into the tank water – instead of pouring it in, it could be injected into the substrate. I have done that over years, for regularly fertilization, but now a day I go with long-term-tabs, that saves time and work.



    Fantastic information Wasserscheu and great pics.


    Something i may have to try in the future



    done everything you guys have suggested

    itll be interesting to see if they perk up i suppose

    the results will take a couple of weeks


    i think i heard somewhere that putting a penny under the roots of

    the Echinodorus amazonicus can help provide iron. ive tried this

    so ill keep my eye open for ill effects

    thx for all your help

    will keep you all posted



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