Oxygenating plants

ok guys, so i'm curious about these "oxygenating plants", how do they work?

i've seen them producing air bubbles, but as far as i know most oxygenation takes place at the surface of the water..

but with these plants, do they inject oxygen directly into the water or is it only the bubbles that they create, that float up and burst on the surface?

 

ever heard of photosynthesis? basically it happens with water plants too.. co2 expelled by fish (or added co2) combines with a lightsource creates a scenario where the plant is able to photosynthesise.. when plants give off these "bubbles" the bubbles mix with the water and actually dissolves some oxygen into the water..

just rem,

co2+light+nutrients (usually fish poop or added ferts) taken up by the plant = by product of oxygen by the plant..

 

photosynthesis i understand, i've even seen the plants release bubbles, but a bubble is not dissolved oxygen, what i'm asking is, does the plant also release disolved oxygen into the water? or rather does the disolving only occur at surface level?

 

Like all aeration, it happens on the surface. If the surface is broken/disturbed. That is why an air stone works better than something that creates bug bubbles. It is better to have thousands of micro bubbles, than a couple of big blobs. I take it the plans release small bubbles in multitude, therefore will be good. What is still a question to me, if you introduce co2, then generally you don't aerate. If you introduce fish, will there be enough oxygen for the fish?

 

I tend to disagree with you there Slimpiet. The bubbles entering your tank through the airstone is not the cause of the oxygenation.. it's the bubble popping on the surface and breaking the surface tension that causes ATMOSTPHERIC oxygen to enter the water. The bigger the bubbles, the more surface tension is broken.

 

http://animals.howstuffworks.com/pets/choosing-aquarium-equipment5.htm

Seems size does not matter when it comes to the bubbles as long as the water surface is disturbed sufficiently enough for it to take place.

 

Normally the surface is broken less frequently with bigger bubbles. The smaller bubbles disturb a larger surface area and therefore i believe it is more beneficial. I might be wrong, but that is my take.
In my tank I don't use any air stones or air pumps as I have a 1M+ drop from overflow to my sump in a 50mm pipe and then enters the tank from the return pump via a very long spray bar. I chose the spraybar for exactly the same reason, otherwise I could have just run a stream of water into the tank. I don't think it would have created the same amount of oxygen in the water.

 

I've thrown a few bunches of hornwort into my old 100 litre tank in the back yard, and it produces so much bubbles that there's a constant crackling sound at the surface with the hundreds of tiny bubbles breaking surface.. Its amazing to see!

 

My logic says the bigger the bubbles, the more "destructive" the bubbles therefore more air

 

Fast photosynthesizing plants like hornwort are often sold as oxygenaters for aquariums and ponds.There ability to quickly and effectively absorb nutrients and Co2 is very desirable in most cases.
Aquatic plants,through photosynthesis,all produce oxygen during the day or during the lighting period.It is only when ample Co2,lights and nutrients are provided,that we witness this as small bubbles or 'pearling'.
In a planted tank,agitation of the water surface is not desirable,because this will drive off essential Co2.It is important not confuse 'surface agitation' with 'water flow' in the planted tank.Although 'surface agitation' is undesirable,'water flow' is very important and necessary for Co2 and nutrient distribution thruoghout the tank.
One of the most satisfying things to watch in a well planted tank,is when all your plants start 'pearling'.When your entire tank looks like a bottle of sparkling water,when you just opened it.Fizzing like Champagne.Nature at work,amazing.

Rudi

 

i dont know, i just wanted to see if plants really produce oxygen in the water, how does it happen and to what degree, i tend to be horribly curious about these things, so i threw the hornwort in the old tank in the back yard, it was cheap and i got a handfull of the stuff for R10.

in the evenings and early morning there are only a few bubbles rising, but when its bright morning or afternoon light, the bubble shoot up in constant streams..


anyway guys who use this method for fish keeping usually do so in a wide-ish pond with much greater surface area to depth ratio, so much more surface area to be influenced by air movement.. not sure if my tank is ideal for an experiment with fish.

i've noticed that the water has gone green, i'm thinking of injecting the water into my own tanks, apparently the free floating algae is very good for fish growth and health, they swim through it and ingest it like that.. not sure if i will do that tho..

still hesitant to introduce the water to my tanks

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it looks exactly like that! like sparkling water!

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actually, when the oxygen bubble floats up, it carries some of the water with it (the water surrounding the "bubble" that is) and this does produce a sort of flow upwards around each bubble tho obviously its not very noticeable. but when you have hundreds and hundreds of these bubbles you can actually see significant water movement..

 

The benefits of green water for raising fry has been proven with people's experience on this forum. I think the key here is that it is used for raising FRY... who are small enough to see the micro parts of the green water. (Not sure what it is green water... just called it micro parts).

The only potential problem I see here is that if you don't have fry in that tank, or at least fish small enough to see the "micro parts" to eat it, this may just land up turning your entire tank green. All it takes is a few spores of the algae from the old tank to cause the other tanks to go green too.

 

zoom i agree with you, my biggest fear is that i may start off an algae problem of sorts, my tanks are situated nicely out of direct sunlight and i have zero algae problems.. my lights are not run for long periods of time as my tinfoils prefer less bright lighting, but i still worry..

about the fry only feeding off the algae, i believe bigger fish can benefit by, for lack of a better term, "breathing" it into there system and thereby growing really healthy.. i have read about this on that thread on green water someone posted a while ago.. but that fact is not backed up by any scientific evidence, tho i would dearly love to test the theory somehow

 

Hi

Just some more information to clarify a point earlier made. All plants produce oxygen under water when they are photosynthesizing, whether you see bubbles or not. The reason you see bubbles is because the plant is producing oxygen faster than the water's ability to disolve the oxygen.

Regards
Lauré

 

What I did not mention is,by the time we see the actual pearling,the water colom is super saturated with oxygen.
So even by not aerating or agitating the aquarium,there is more than sufficient oxygen in the water for fish.It is only at night when you could encounter problems.That is one of the reasons why a electronic solenoid should always be used when injecting pressurized Co2.

Rudi

 

ok this exactly the answer i was looking for. i thought it was only the rising bubbles breaking the surface of the water that was doing the oxygenation..

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i've added one one those DIY CO2 things with the yeast and sugar water, but it only produces like one biggish bubble per second or so.. its not a stream of bubbles.. is that right or should there be much more bubbles?

 

Hi mydummyname

You should google CO2 diffusion methods, or refer to the numerous CO2 threads on this forum. You need a device at the end of the CO2 tube that will break up the one big bubble into many tiny bubbles. I single CO2 bubble will only rise to the top of the water and will do absolutely nothing for your plant growth. A good method is to buy a small pump and insert the end of the tube into the pump so that the bubble flows through the pump's impeller, which will chop it up into hundreds of small bubbles. These smaller bubbles will dissolve much quicker into the water, which is what you want. The other advantage is that the pump will create a flow pattern, and if directed towards your plants, some of these small CO2 bubbles will be trapped under leaves and increase the effect the added CO2 has on plant growth.

Regards
Lauré

 

ok cool, but the rate of 1 bubble per second, is that about correct? or should it be producing more?

i'm not too worried about the CO2 tho, i really thought it would produce a lot more bubbles, like an air-pump, then you could stick the end of the line into a piece of filter foam and have a non-electric filter, but at the rate of 1 bubble per second that would never work, unless you hook up like 10 bottles of the stuff lol, but then there would be too much C02 in the tank i think..

but besides all that, the tank now looks like very gassy cream soda with all the bubble the plants are making lol its quite amazing to watch

 

well depens on the size of your tank, equipment etc..

for instance, i have a 23l nano heavily planted with high intensity lights over them (20wx2) and i use my co2 at 1 bubble per second.. in my 63l, lights arent as strong, i also use 1bubble per second.. so u also have to judge for urself.. else get a co2 montior.. those ones with the solution arent too expensive..

 

ok then 1 bubble per second sounds about right... i might experiment with different mixtures to see if i can get it to produce more bubbles...