What Co2 Diffuser

[BigBadBurrow]

If you've not used a reactor then, with all due respect, you don't really know what you're talking about because you've not got the experience.

It's very simply to monitor how much diffusion you're getting - look how many bubbles are reaching the surface. The example you posted is an example of poor diffusion - look at all the bubbles that are simply rising to the surface and escaping out the tank. That's not diffusion my friend, that's wastage.

I am getting 100% diffusion using the system shown on this page:

http/www.co2supermarket.co.uk/products/co2-mixer-reactor-diffuser.html

How do I know? Because NO bubbles exit out of my filter outlet - none. All of the CO2 is diffused in the water. The one enhancement I made it to put a piece of course foam in the cylinder to stop any rogue CO2 bubble sneaking out.

Like I say, it's a bit more effort to set-up, but well worth it.

 

[ian]

i'm beginning to think you may be working for C02 supermarket!

even they say you don't get 100%, they say nearly 100%, which isn't 100%. I can read, i know people who use reactors, just because i haven't used one, it doesn't mean i have no experience in reactors.

Please show me the testing done to prove 100% diffusion rates. please do, because i doubt you can provide any.

The example you posted is an example of poor diffusion - look at all the bubbles that are simply rising to the surface and escaping out the tank.

mmmm i think that was actually posted by yourself. I posted the Rinnox, and the bubbles are blowing around the diffuser.

ps to anyone reading this thread the Diffuser is available on ebay, for a lot cheaper and you could even make your own.

 

[BigBadBurrow]

And I'm beginning to think you're a bit dense. I bought it from them, so that's how I know about the video. Big deal.

They probably weren't getting 100%, I am, because as I've said twice now - I've added some foam to stop any rogue, un-diffused bubbles getting out.

"just because i haven't used one, it doesn't mean i have no experience in reactors."

Well yes it does, you've not used one - what a daft thing to say. I've used nano diffusers and reactors so I think I probably have more experience in the field that you do.


"mmmm i think that was actually posted by yourself. I posted the Rinnox, and the bubbles are blowing around the diffuser. "

Yes, I know what you posted, I saw it and wasn't impressed at all; your video shows some bubbles being blown a bit - big whop! That's not diffusion, that's some bubbles being blown around a bit. If you can see a bubble then it hasn't been diffused. It's a very simple concept, but one you don't seem able to grasp.

I never thought I'd get into an argument about what type of diffuser is best, especially when there's clear evidence to back up which are better than others.

 

[BigBadBurrow]

Sorry, I feel bad about my last post, I overreacted. It's just I do feel rather offended when I try to offer help, based on actual first-hand experience, and I'm then basically told I'm wrong and insulted by someone who doesn't have the same experience.

I've said my piece and made my recommendation, that's all I was wanting to do to help the guy out. Hope someone finds it useful

 

[SuperColey1]

If you've not used a reactor then, with all due respect, you don't really know what you're talking about because you've not got the experience.

It's very simply to monitor how much diffusion you're getting - look how many bubbles are reaching the surface. The example you posted is an example of poor diffusion - look at all the bubbles that are simply rising to the surface and escaping out the tank. That's not diffusion my friend, that's wastage.

There are 2 lines of thought here. Many say misting is best because the small bubbles break through the leaf barrier better than '100%' diffused. That is one reason why many of the most respected do not use reactors instead going for diffusers/needle wheels etc. They want bubbles, not 100% diffusion.

Your second paragraph is mostly wrong. Locical when thinking about it simply but wrong still.

Step back a second. The bubble that hits the surface is wastage. that is where the statement's correct line of thinking ends. It isn't poor diffusion. A ladder will be 95% efficient yet you will still see a bubble reaching the surface. 95% diffusion (or I think it was actually 94%) is pretty darned good.

How is this possible and how can someone have known that? If a bubble rises you can see it getting smaller as it rises. that is CO2 diffusing. You can then see the bubble get to the surface. That is wastage.

The bubble at the bottom of theladder is pretty large. The bubble that hits the surface is much much smaller so the people who love to work these things out can do measurements and work out the volume at the bottom and the volume that hits the surface.

With the reactor you will get near 100% (not 100%) diffusion in the water. However it will still gas off. Problem is that you cannot visibly see the gassing off. It may be gassing off more than the bubbles but as it is in solution there is no visual sign.

The ladder is more efficient than the disc diffuser then why do we use the disc diffuser?

See my first statement. Because we want bubbles (or mist) to hit leaves. Its much much easier and more beneficial for us to use something that produces teeny tiny bubbles than large ones. They are easier to push around the tank, in fact very easy to keep in the water all the time.

Couple this with the fact that you can stick the diffuser in the flow to move the bubbles. Try this with the ladder and the bubble comes off the ladder and zooms to the surface defeating the way it diffuses.

So forget about 100% diffusion. That is not the point. Getting CO2 to the plant's leaves is the point.

That is why many many top aquascapers or plant growers use diffusers, internal or external, glass or plastic or otherwise, Needle Wheels and other gismos rather than reactors.

Now of course not all do. Just a large proportion. Most wil agree however that it is easier to use a reactor on a larger tank.

The key to both a reactor and a diffuser is not efficiency of the CO2 equipment. It is flow and circulation within the tank. You have to keep the circulation and flow working well to transport the CO2 (whether diffused or as bubbles) around the tank. It is much easier to do this with bubbles or mist quite simply because you can see it with your own eyes and alter things until you see that you are being succesful.

Add to this that whether using a diffuser or reactor and even with the ultimate perfection in circulation and flow you will still 'lose' 95% of the CO2 you pump in to the atmosphere. This is unavoidable.

I've used them all. Ladders, Needle Wheels, Reactors, inline and internal diffusers.

The Rhinox was by far the best internal. Better than al the other glass ones I tried. Was better for me than the Boyu External which was also good. The Up inline atomiser blasts both into the distance. these new atomisers are really the DBs but I would suggest to be careful because they are bound to gain a 'knock off' replica now.

I never really liked the reactor. Couldn't see what was happening as stated above. Didn't like the Needle Wheel in the end. It was awesome at the job but unsightly in the tank.

I do know many who are very happy with reactors though.

Each to their own but lets not get on the Mine's better than yours bit r.e. Reactors or Diffusers. Its user choice and many more favour the mist than the invisible for varying reasons other than cos me mate uses them or they like glass. Many diffusers are actually rubber, plastic etc. Not just pretty glass things

Andy

 

[ian]

BigBadBurrow, even though i have never used a reactor, i have used every other method of C02 diffusion. I'm really not that 'dense'. If the reactor is working for you then carry on. At know point did i say they didn't work, i just mentioned that flow is slowed by them. Andy has made a really good post regarding diffusion. Try not to take things to personally. C02 is one of the hardest things to measure in a tank.

 

[BigBadBurrow]

"Your second paragraph is mostly wrong. Locical when thinking about it simply but wrong still."

No, it's completely right. You do realise that CO2 bubbles hitting leaves is not diffusion, and leaves dont absorb CO2 in that way? The aim of difussion is to diffuse the CO2 in the water.

CO[sub]2[/sub] + H[sub]2[/sub]O = H[sub]2[/sub]CO[sub]3[/sub]

This is cabronic acid. You'll know that as a result of putting CO2 in an aquarium it lowers the pH - why? Because you've effectively added carbonic acid to your aquarium, and acids are lower in the pH scale.

CO2 bubbles hitting leaves does not mean the leaves absorb the CO2 - they bounce off and rise to the surface.

If you want good difussion then you don't want to see bubbles floating around your tank and eventually hitting the surface. It might look pretty, but it isn't an efficient system.

I dont know why you seem to have such a hard time of grasping the fact that if you see a bubble hitting the surface then it's wastage - that CO2 has NOT been absorbed, it's waste. And to that end, a CO2 reactor is by far the most efficient diffuser because it traps the CO2 and doesn't allow it to escape.

The whole purpose of a ladder is to extend the amount of time the CO2 is in the water, why? To enable it to diffuse. Which is why the bubble at the end of the ladder is smaller than it is at the start. But there's still a bubble at the end, so it's not efficient, is it? Using a reactor does the same thing but traps the CO2 so it can't escape and has no other option than to be diffused.

I'm honestly dumbstruck as to how many people don't seem to have the mental capacity to grasp what is a very simple concept.

 

[SuperColey1]

Diffusion is theree o make it easier to keep some of the CO2 in the water.

You shouldn't go on the berating those with statement like unable to grasp and lack of mental capacity. Do some research first.

Yes a reactor is the best at diffusion BUT it has long been discussed about the merits of teeny bubbles.

It most definitely is nothing to do with bubbles going round the tank making it look pretty. Many people who use reactors do so because they hate the 'fizzy pop' appearance of the water!!!

Reactors aren't expensive. They are much cheaper than many of the top diffusers and if reactors were the ultimate then why would so many use diffusers? Why are they nearly all transferring from diffusers to the new atomisers and not to reactors?

If you think reactors 'stop' CO2 escaping and that CO2 is 'trapped' in the water you are totally mistaken. Things go into solution and out of solution just as easily. Just that with a diffuser you can se it happening and with a reactor you can't.

Rather than try to convince you myself I shall put some links up. You can then tackle those people who research to the max.

Some reading (will find some better ones later as I have to take my kids to the dentist but these are good enough for now.:
http/ukaps.org/forum/viewtopic.php?f=35&t=15268&hilit=colour+chart&start=10
http/www.ukaps.org/forum/viewtopic.php?f=37&t=16122

As I said don't concentrate on the diffusion so much. diffusion is not distribution and most definately doesn't have anything to do with how a plant uses CO2. Diffusion is just the form the CO2 is in. That doesn't mean that in solution CO2 is of no use. It is fine and works well. Just that in scaping most people want very fast, very lush growth and they would use whichever method achieves this is what they will use. There is a reason most are using misting techniques whether it be teeny bubbles or fine atomised fog mist.

With 10,20,30x filterr turnover vs tank volume there isn't much problem shifting bubbles around the tank and making them push all the way around without ever hitting the top. That doesn't mean that CO2 that goes into solution on the journey around is saved though. It will still gas off just like it will from reactor dissolved but the process is invisible.

The water will always try to return to equilibrium levels.

By my recollections the AM1000 Reactor (1.5bps) used more CO2 than the UP atomizer (0.8bps). Did use less than standard ceramic disc diffusers though (2-3bps) but not much.

CO2 bubbles hitting leaves does not mean the leaves absorb the CO2 - they bounce off and rise to the surface.

Have you seen this happen? Bouncing off leaves? Strange. For the rest of us these tiny bubbles stick to the leaves as long as we can keep them moving without hitting the surface.!!!

Andy

 

[BigBadBurrow]

I think people use glass diffusers because it looks pretty having the bubbles and it's easier / cheaper to implement than some other solutions.

Have you seen this happen? Bouncing off leaves? Strange. For the rest of us these tiny bubbles stick to the leaves as long as we can keep them moving without hitting the surface.!!!

It might rest on the leaves but that doesn't mean it's absorbed - there's a big difference. Aquatic plants don't have stomata for gas exchange - why? Because they're aquatic so there is no gas surrounding them, so they've evolved not to have stomata and physically cannot absorb gas through its leaves - that's a fact.

 

[ian]

can you back these facts up, and tell us how plants absorb the C02 around them?

CO2 gets absorbed through leaves, aquatic plants have adapted to carbon dioxide limitation in several ways. Aquatic plants have thin, often dissected leaves. This makes an increase in the surface to volume ratio and decreases the thickness of the unstirred layer. They have extensive air channels, called aerenchyma, that allow gases to move freely throughout the plants and leaves. This allows respired carbon dioxide to be trapped inside the plant and in some species even allows CO2 from the sediment to diffuse into the leaves. Finally, many species of aquatic plants are able to photosynthesise using bicarbonate as well as CO2. I turn we end up with the pearl effect.

 

[SuperColey1]

I think people use glass diffusers because it looks pretty having the bubbles and it's easier / cheaper to implement than some other solutions.

Have you seen this happen? Bouncing off leaves? Strange. For the rest of us these tiny bubbles stick to the leaves as long as we can keep them moving without hitting the surface.!!!

It might rest on the leaves but that doesn't mean it's absorbed - there's a big difference. Aquatic plants don't have stomata for gas exchange - why? Because they're aquatic so there is no gas surrounding them, so they've evolved not to have stomata and physically cannot absorb gas through its leaves - that's a fact.

Well done on reading the links I supplied. I will supply more just finding them now but you are going to struggle with your argument. No-one has diffusers because they like 'pretty bubbles' I for sure like my water gin clear with no obstruction to the view in the slightest.

Cannot absoprb gas through their leaves? My goodness you are way wrong there.

Your statements sound exactly like those that argue about red and blue spectrum lighting and that green is useless. they always say FACT to. however they cannot (or will not) explain why those who use actinic, or green lights get as good growth as those who use supposedly full spectrum plants.

More links for you to choose or not to read will follow, however the Op quesiton was which diffuser not diffuser or reactor so we are off topic here.

Andy

 

[ian]

we are way off topic...

to bring it back down and get on track.


Reactors are OK as are glass diffusers.

 

[BigBadBurrow]

can you back these facts up

It's a biological fact that aquatic plants don't have stomata - there's no need for them because they aren't surrounded by gas. So if you deposit a gas bubble on an aquatic plant leaf if wont be absorbed by the plant because there's no physical way for it to be absorbed.

tell us how plants absorb the C02 around them?

An aquatic plant absorbs CO2 through diffusion and osmosis; the transfer of molecules from an area of high concentration to low concentration through a semi-permiable membrane. Dont forget, the CO2 is no longer CO2, it's H[sub]2[/sub]CO[sub]3[/sub], and therefore the plant can absorb it without needing stomata.

Aerenchyma are internal tissues in a plant and are responsible for the flow of oxygen within the plant itself.

Hopefully we've established that aquatic plants can't absorb CO2 gas through their leaves - they can't they don't have somata. So saying it's actually beneficial to have the bubbles in suspention in the water for the plants to directly absorb isn't true. Instead, what you're basically doing is keeping the CO2 in the water as long as possible until it eventually diffuses in the water.

If you're directing your flow of water & bubbles around your tank to ensure the bubbles never escape out the top, then you're doing exactly what a reactor is doing, but a reactor does it in a more confined space and with better efficiency.

If you like the look of bubbles then there's nothing wrong with that - I like the look of it too, but I much prefer not wasting CO2 by seeing it escape out the tank un-diffused in the form of bubbles. But to say you get just as good diffusion using a nano and directing the bubble stream into the flow from the filter is as good as using a reactor simply isn't true; far too much CO2 escapes out the tank un-diffused.

 

[SuperColey1]

what should concern us is the CO2 that we get past the Prandtl boundary layer along the plant leaf.

This statement from elsewhere suggests you are very wrong in your belief on gas and leaves is most definitely incorrect.

In effect the good Professor Prandtl, has defined a number of problems we face in getting our, plant friendly carbon disbursed. with respect to the movement through the water, the aforementioned Prandtl also has a number that adds to our problems in affecting that perfect circulation for CO2 as well as nutrient distribution we all seek.

You may see the 'leaf boundary layer' is a common topic in most of these threads. If the leaf 'cannot physically absorb gas through it' then why are these educated (unlike myself ) folks continually including it in their discussions?

If you don't want to read all then definitely read this one. It has all the science speak you seem to like from above. Most definitely talks a lot about mists and boundary layers:
http/www.barrreport.com/showthread.php/4977-CO2-leaf-morphology-and-uptake-relative-to-current

http/www.barrreport.com/showthread.php/2802-Optimal-concentration-of-co2

http/www.barrreport.com/showthread.php/4731-Are-we-missing-a-much-more-simple-CO2-solution

http/www.barrreport.com/showthread.php/3485-Water-circulation-and-CO2


At the end of the day as you will see on many posts I make in these types of thread it is user preference at the end of the day. Most aren't after that ultimate growth, they just want to use CO2 efficiently and see the plant anjoying the CO2. Most who want ultimate growth and use the least CO2 possible have come off the reactor program onto the misting program over recent years. Not all and some stay on the reactor program for good reasons...namely because it works for them and thats how it should be.

Reactors or diffusers? They both work. they both have nay sayers and they both have fan boys however its not about a mine is better than yours concept. It is about mine works well for me and I happy with it concept.

Amdy

 

[BigBadBurrow]

@SuperColey

Cannot absoprb gas through their leaves? My goodness you are way wrong there.

I don't think soooooo. Tell me, how do they do it then without Stomata?


Here's just one of many many pages on the Internet that say exact the same thing:

http/www.eoearth.org/article/Aquatic_plants?topic=58075

"Leaves of submerged aquatic vegetation lack stomata, the pores in the leaves through which terrestrial plants exchange gases such as carbon dioxide and water vapor with the environment."

I can provide many many more sources if you wish?