Air Stones....

[raptorrex]

however for those who do (look after their tank properly) airstones are for looks, and current.

Just out of curiosity, can you elaborate on what proper looking after a tank is?
Seems I have a problem as without the air pump set on high the fish started gasping in the morning. I would love to know how to fix that as I am sick of looking at the tubes running in.

wow, a big and important question. mind you i could do with the tank dimensions.

at its most basic, it means a cycled tank. with a degree of surface disruption. that is treated to regular water changes. with its substrate, sufficiently cleaned.
going deeper. we would hope for a good flow around the tank in general. together with guarding against build-ups of waste, in any closed or tight areas. (caves ornaments and corners.)

as a beginner (first two or three years) water testing is a must. if for no other reason than learning how your tank reacts to different situations. as time goes on, you will test less (if you wish), many of us finding that tests are only needed IF a problem shows up.
how do you determine "if a problem shows up"? you use the experience you have built up.

incidentally, fish swimming and gasping at the surface. is not, always, related to the waters O2 content. as often as not, this is related to filtration. even if an airstone, seems, to solve the problem.

it must be noted that Duel, specifically, warn against using an airstone, on all their tanks. indeed it invalidates the tanks guarantee. now would they do that if airstones were , necessary or important to a well kept tank?

I really cant reiterate how important the "search" function of this forum is.
most of these threads have been done before, and all carry the advice and knowledge of years.
I will warn you, mostly, need to go back a few years.
but its worth it. and it avoids getting lead astray, by "NEW THINKERS". especially when they come with not one shred of, real, evidence. and ignore that which is put to them.

 

[snazy]

Thank you.

wow, a big and important question. mind you i could do with the tank dimensions.

60 cm wide, 40.5 cm width, 50 cm hight. Tank capacity 130 litres. Water in tank 100 litres as I measured it the first time I put the water in, rest must be substrate and decorations.

at its most basic, it means a cycled tank. with a degree of surface disruption. that is treated to regular water changes. with its substrate, sufficiently cleaned.
going deeper. we would hope for a good flow around the tank in general. together with guarding against build-ups of waste, in any closed or tight areas. (caves ornaments and corners.)

Tank is cycled. It's been tested weekly and never detected ammonia/nitrite. Nitrite rises to about 40 before water change of 50% once a week, sometimes 2 water changes of 25% twice a week depending on how busy I am. Gravel is siphoned to the bottom on different stages at water change. Never siphoned all the gravel at once though, and can't properly clean the planted area which is mostly at the back and sides of tank, not in the middle, but there are quite a few plants. Water is always crystal clear even though that's not always proof for water quality. Fish colour is in great condition, corydoras spawning and guppies and platies endlessly giving birth They don't seem to eat the fry anymore. Survivers fry get moved in another tank and a third tank is going to be cycled soon for the expanding population.

as a beginner (first two or three years) water testing is a must. if for no other reason than learning how your tank reacts to different situations. as time goes on, you will test less (if you wish), many of us finding that tests are only needed IF a problem shows up.
how do you determine "if a problem shows up"? you use the experience you have built up.

I am not really a beginner, but had a break of fish keeping for a while. First thing I do when I am in doubt of anything is test the water. It's been done every week and sometimes in between when I have nothing better to do

incidentally, fish swimming and gasping at the surface. is not, always, related to the waters O2 content. as often as not, this is related to filtration. even if an airstone, seems, to solve the problem.

I know that. Problem is tank has 2 filters with total flow of 1800 litres an hour. As previously explained that even makes it 18 times the water volume an hour as I forgot to exclude the volume of the gravel and such the last time. Water is blowing at the surface and looks like an ocean there. Fish love it and play in it. The air pump is marina 200 rated for Tanks 125-225L.
I really don't know if decreasing the flow of the water pump was the problem, but that's what I thought at the time. I can maybe try again and see what happens. Since there are a lot of live plants, I presumed they were taking too much oxygen at night, as fish were at the surface only in the morning for an hour or so.

it must be noted that Duel, specifically, warn against using an airstone, on all their tanks. indeed it invalidates the tanks guarantee. now would they do that if airstones were , necessary or important to a well kept tank?

Interesting...My tank is not in warranty, but wondering what is behind such statement? Preinstalled filter defect?

I really cant reiterate how important the "search" function of this forum is.
most of these threads have been done before, and all carry the advice and knowledge of years.

I'll do that. Thanks.

I will warn you, mostly, need to go back a few years.
but its worth it. and it avoids getting lead astray, by "NEW THINKERS". especially when they come with not one shred of, real, evidence. and ignore that which is put to them.

I really don't have enough evidence for that, as my other tank is without an air stone and works fine with the one filter in. But I have no plants in it to use additional O2 at night. Just to not that I don't add CO2 to the tank at all, or any other ferts.

Anyway. Thanks very much for the reply. I'll leave it at that as it is not my post. I'll test the tank without an air stone running as it may be also taking out too much CO2 for the plants to photosynthesise.

 

[raptorrex]

it must be noted that Duel, specifically, warn against using an airstone, on all their tanks. indeed it invalidates the tanks guarantee. now would they do that if airstones were , necessary or important to a well kept tank?

Interesting...My tank is not in warranty, but wondering what is behind such statement? Preinstalled filter defect?

no, not a filter defect. (though in my opinion duel filters are junk) I'll go into this in more detail, if you like. using Duels own information. but in a PM or separate thread.
turns out, their problem is cavitation. they worry that any weakness in the tanks seal, may be undermined by, air and water cavitation. (essentially they worry that airstones may cause leaks). and, as they are not necessary (airstones) state their uses, invalidates the guarantee. though, my feeling, is its more to do with, potentially, poor quality control.
there really can be now more compelling evidence of the optional nature of airstones, in our hobby. because, if they were, "necessary". Duel would be open to class action suites. and would no doubt have lost many..
incidentally, all the above is in a thread, on this forum. including, I think, the letter, or comment, from Duel.
dont worry too much about this not being your thread. you have asked, possibly, the most sensible questions, on here. and many read, without commenting. your question may be just what they are looking for.

 

[snazy]

Thanks very much. That explains a lot.
As for the air stones, it's good to know they are not essential anymore with quality filtration. Years ago all I used was sponge filters and air stones, and the occasional undergravel

 

[fishguy2727]

Just because someone hasn't been on here long enough to be harassed in to either giving up on sharing their opinion or being brainwashed doesn't make their opinions any less valid.

Saying over and over that someone else is wrong for not sharing any factual evidence while not sharing a single shred of factual evidence yourself puts you in the same boat.

There is such a thing as forum bandwagoning. This is when one or a few people on a forum have a certain point of view and any time the topic comes up they jump on it and say the same thing over and over again until the people reading the thread are convinced. Then the next time the topic comes up the original people and more hop on saying the same thing over and over again. Anyone with a differing opinion is simply swallowed in a sea of 'I agree' or argumentative posts until the new person thinks the majority are correct. So in the end anyone with a different opinion gives up because there is no hope or eventually buys in to it themselves. So searching through one forum will only tell you what the people who have been there the longest think. This doesn't prove anything except that some people simply post over and over again and convince others of their way of thinking. I have seen this on many forums and it seems like this subject has it here. 'Believe us because we have said it before'.

Look back at this thread. Read the posts. There are many opinions on here, many questions, and a lot of repetition. People have asked good questions that were never answered. Why do air bubbles drive off CO2 if they don't aerate? What is the minimum contact time between air and water for aeration to occur? The idea that bubbles do not aerate implies a minimum contact time. If this were true it would also be true of air at the surface, making too much flow at the surface prevent aeration. If bubbles do not aerate then how do protein skimmers provide all needed aeration in a saltwater tank? If bubbles do not aerate then why do sewage treatment facilities and commercial aquaculture use bubble aeration? For decoration?

If the fish are gasping and it stops when you add aeration it really wasn't a lack of aeration causing the problem? Really?

One person is arguing against this the hardest without providing any factual information to support their idea they are simply saying that I am wrong, yet states that I am stupid, saying rubbish, not qualified because I haven't been on here long enough, and haven't provided any evidence, all while not providing any factual evidence for his own opinion.

I never said every tank will always need air stones. The entire time I have said that I recommend them for every freshwater tank because I have seen filters stop for different reasons and the fish were saved by the air stones alone too many times for me to not recommend them. It is a cheap, easy, no maintenance piece of equipment with the potential to save the whole tank's livestock. Even if that never happens there are definite benefits to having one including increased aeration and flow, and many fish enjoy them.

 

[ian]

is that not written by yourself?? which makes it totally anecdotal and that for me and many others is purely based on opinion. Which again this thread is mainly based on.

Why do air bubbles drive off CO2 if they don't aerate?

As we know C02 is classed as a trace gas (trace being the right word, as there isn't much of it). Oxygen is not a trace gas, there is plenty of this stuff around. There is a lot more 02 than C02 in water, when we over aerate in a planted tank (see i said planted tank, if you read back i will always reference planted tanks), the C02 becomes a lot less than the 02. As we know plants need C02 to thrive and gassing the 02 off with airstones isn't a good idea, unless you're running pressurised C02, as you can control the pressurised stuff. As said again, in a planted tank, especially using such methods as the Walstad, would be a complete waste of time.

What is the minimum contact time between air and water for aeration to occur?

I'm not sure if you mean the raw 02 bubbles in the water ot the surface area on the top of the tank IE current from the outlet?

the saltwater question i cannot answer and is there any chance of a link for the sewage works using bubble aeration, that sounds interesting.

 

[snazy]

As we know C02 is classed as a trace gas (trace being the right word, as there isn't much of it). Oxygen is not a trace gas, there is plenty of this stuff around. There is a lot more 02 than C02 in water, when we over aerate in a planted tank (see i said planted tank, if you read back i will always reference planted tanks), the C02 becomes a lot less than the 02. As we know plants need C02 to thrive and gassing the 02 off with airstones isn't a good idea, unless you're running pressurised C02, as you can control the pressurised stuff. As said again, in a planted tank, especially using such methods as the Walstad, would be a complete waste of time.

I wasn't going to post, but I have too many questions

Most of the googling I did on the subject says that air pumps do aerate, but it's not by driving bubbles in the water, but rather the bubbles bursting at the surface. So if you have it set to low, it won't do too much and power heads and protein skimmers are better for that.

I was also wondering, based on the quoted text about the CO2 being a trace gas...and air pumps driving the CO2 off. Isn't that the case with power heads as well? I mean the CO2 does not know if it's been driven off the water by an air pump or powerhead. So if in general a tank has too much surface movement for aeration one way or another, it will drive the CO2 out of the water anyhow. Or how does it work if that's not the case? Also, even if CO2 is a trace gas, and an air pump is able to drive it off the water, then the same amount of trace gas will come in from the air via the exact same process, or how is the relation calculated?

 

[coldcazzie]

Most of the googling I did on the subject says that air pumps do aerate, but it's not by driving bubbles in the water, but rather the bubbles bursting at the surface.

Yes, because that increases the surface area, leading to more gas exchange.

Isn't that the case with power heads as well? I mean the CO2 does not know if it's been driven off the water by an air pump or powerhead. So if in general a tank has too much surface movement for aeration one way or another, it will drive the CO2 out of the water anyhow.

Yes, exactly. Which is why in a planted tank sometimes the recommendation is to lower your filter outlet so that it causes less surface agitation, thus leading to less gas exchange at the surface. And then at night (ie, when the co2 is not being absorbed by the plants) an airstone can be run to increase the surface agitation again (this is much easier than moving your filter every 12 hours!) thus making sure that the fish do not die of carbon dioxide poisoning. This is one of the alternatives to using a solenoid valve which shuts off the co2 at night.

 

[snazy]

Thanks
So the air pumps are not for decoration and do help in gas exchange at the surface, although that depends how strong the air pump is. So they are not as efficient but more flexible

Edit: But doesn't some amount of CO2 enter the water via the same process?

 

[ian]

but think about it Snazy, airstones don't push the water back into the tank, this is what the filter outlet does...think about how the filter outlet pushes the water around the entire tank. An airstone doesn't do this, it breaks the water surface, it doesn't push the water back into the tank. It will give minimal aeration, it gives aeration yes, but it's minimal.

and yes you will get some C02 enter the tank via aeration, but as we know, there is more to planted tanks than just getting a little C02 from the air. Take for example, the Walstad method, you have to have low lighting. Lower the light less demand on the plants. Also the substrate in Walstad tanks let off a steady amount of C02. Not a massive amount, but enough to keep equilibrium.

 

[Bignose]

Look back at this thread. Read the posts.

To everyone else reading this thread: FG and I have tussled on this topic several times before. I am not even going to bother presenting my side of the argument again except to note that this: http/www.fishforums.net/index.php?/topic/377186-a-rational-discussion-on-oxygen-transfer-from-an-airstone-bubble/ is a thread that contains links to both sides of the discussion. Feel free to peruse it at your leisure.

 

[DevotedToDiscus]

Thanks
So the air pumps are not for decoration and do help in gas exchange at the surface, although that depends how strong the air pump is. So they are not as efficient but more flexible

Edit: But doesn't some amount of CO2 enter the water via the same process?

I would doubt it very much.....Air only contains 0.0314% of Co2..... It is mainly Nitrogen 78% and Oxygen 20%. This is why we use pure Co2 in pressurized systems for plants.

I am sure this will stir up even more trouble!

 

[ian]

no you're right DTD, as said above C02 is classed as a trace gas, and again you're right, this is why we tend to use pressurised systems. We have to remember that the majority of out plants stay out in the open air for half of the year where they receive 380ppm of C02, then the rains come and flood the plants and they then only receive around 30ppm of C02. This is why we aim around that number in an home aquarium.

 

[DevotedToDiscus]

no you're right DTD, as said above C02 is classed as a trace gas, and again you're right, this is why we tend to use pressurised systems. We have to remember that the majority of out plants stay out in the open air for half of the year where they receive 380ppm of C02, then the rains come and flood the plants and they then only receive around 30ppm of C02. This is why we aim around that number in an home aquarium.

Thanks ianho

.......Is nice to know from someone of your caliber that I don't speak complete drivel all the time, just sometimes

 

[snazy]

no you're right DTD, as said above C02 is classed as a trace gas, and again you're right, this is why we tend to use pressurised systems. We have to remember that the majority of out plants stay out in the open air for half of the year where they receive 380ppm of C02, then the rains come and flood the plants and they then only receive around 30ppm of C02. This is why we aim around that number in an home aquarium.

That's because you want the plants to look the best and we also keep plants together that are probably never seen in the same spot in nature.
Someone posted a video recently here of the Amazonian river and lakes and those Amazonian swords looked pretty rough

Obviously there are ways without a pressurised CO" system, like the Diana Walstad method. And from what I have read, the downside of the Walstad method is that not all plants can be kept, but once established, it's all fine.