Oxygen Question

[White Worm]

Ok,,, Maybe someone can explain this to me in lame terms. We talk about airstones / aeration. OK.. Just surface agitation gases off c02 which helps oxygen levels increase right, thats why we use the bubbles? Doesnt the bubbles from the sponge filters do the same thing? Should I put an airstone inside the sponge filter and kill two fish with one stone? (Get it?) Whats the difference between airstone, bubble wall, etc? Wouldnt just bubbles coming right out of the end of the air tube do the same thing? I have two sponge filters running and inside the filters I have the white diffusers (its not an actual stone) I think it is mainly to make the bubbles smaller. What should a running tank have as far as air? Mike

[RyanH]

Anytime bubbles break the surface tension of your water gas exchange will occur. It doesn't really matter too much IMO, how big those bubbles are. So the air from your sponges is already killing two birds with one stone. :)

I like to use airstones or diffusers in my sponges because I think it gives me better water flow for biological filtration. This is my personal preference.

As far as adding extra airstones to your tank goes, if you don't have fish at the water surface and gasping for air, then they are probably fine. Just remember that the warmer the water, the less oxygen it is able to hold. So if you are raising your temps to treat for a disease for example, adding another airstone is probably a good idea.

hth:)
-Ryan

[Alight]

Actually the amount of diffusion of O2 and CO2 increase due to the bubbles themselves is negligible, as Ryan suggested. It's really the convection of the water to the surface that is important. The sponges filters do this just fine. So will a power head that has no bubbles at all.

[JimmyL]

The difference is the surface area expose between air and water. Our lungs diffuse oxygen from the air we breathe to the blood through a bunch of airsacs that look like a bunch of grapes called Alveoli. The surface area is eqivalent to the size of a football field if you cut them up and lay on the floor. Comparing the surface area of a pair of lungs without airsacs which is approx. 1 square foot. So size of bubbles plays an important role of oxygen diffusion and temp. affact the amount of dissolved oxygen that is more important than just 21% of oxygen at room air. As for the sponge filter. The driving force generated from a large rising bubble is more important than oxygen diffsuion by a bundh of tinny bubbles mainly the purpose is the force needed to suck the surrounding water through the filter. Therefore the extension tube is very important to create negative pressure.There is a big difference between airstone and sponge filter. We can't mix them togehter.HTH
Jimmy

[White Worm]

That sems to be a tough one. I think I got two different answers here. One says to combine and one says seperate, hmmmm. Surface agitation seems to be the overall key factor here. Does anyone ever measure amount of oxygen in their tank or is there a way to measure it? My guys dont gasp at the top of the water so I dont think I have a problem, I was just curious.
Jimmy,,, Could you simplify a little for me. So, what you are saying is bigger bubbles are better for oxygenation? Then what are the airstones for? Wouldnt air just coming out of the end of the air tube be just as suffucient?

[Carol_Roberts]

One hang on the back filter like an aqua clear 110 or two airdriven sponge filters like hydro IV are all that's needed for oxygen in a 55 gallons discus tank kept between 82 - 86 degrees. Higher temps (like the 92+ for metro treatment) need more O2. With a hang on the back filter like aqua clear, you can lower the water level a half inch to increase surface agitation . . . or add an airstone :)

[White Worm]

Hi Carol,,,, One more question? When filling tank, where do you fill to. I always fill to where you cant see the water level through the glass. Does it make a difference? I know these are some dumb questions but just some things that I have always been curious about. Whenever i see pics of breeder tanks, it seems like they leave about 1" from the top??????

[Mack]

The space you see is usually necessary if the bulkheads are drilled on the top back of the tanks rather than the bottom.

[candyl70]

Hey Mikey,
I think that leaving half an inch makes the water splash a little more at the top, increasing the airation. It breaks more of the surface water.
You don't have to do it, if your fish are ok and not gasping. Sometimes i leave a little room at the top because the babies like the warmer water. I just like to be sure that they are getting enough O2 which they seem to be getting.

hth, i'm not sure i made any sense:p


C~

[pcsb23]

The purpose of the air going through a sponge filter is to create a current or flow of water through the actual sponge material, the extension tube on the top of most sponges channel the air upwards to the surface, this creates less pressure at the bottom of the tube, in effect creating a mild suction. Therefore it draws the water through the sponge. To demonstrate this next time you do a water change, if its safe to do so (no exposed heaters or not too shallow for the fish) take the water level to about an inch below the top of the tube on the sponge and the water will still rise out of the tube and flow back into the tank (if it doesn't turn your air up!!) The beneficial by product of this is to break or dusturb the water surface which is the only place oxygen exchange can take place. As Carol said if you raise the temp add an airstone, if your fish gasp at the surface also add an airstone.
hth,
Paul.

[White Worm]

More surface agitation, makes sense to me. The only problem with the water splashing in at a lower level is lots of little bubbles in the water. Hard to see fish as clear. I guess there has to be a compromise huh? As long as they are healthy and happy, it works for me. Thanks for everyones input.
Yes I have seen water flow out of the tube when the water level is below the tube. I guess mine is working good then. Thanks

[Carol_Roberts]

For water levels in tanks . . . with HOB filters like aqua clear I leave about 1/4 inch of glass showing under the top rim. I leave more space with sponge fitlers so the bubbles don't hit the glass top - saves cleaning scum and algea off the top glass.

[Alight]

For tank levels, I do what Carol says.

In breeding tanks, some lower the levels so that the fry can more easily find the parents when they become free swimming. They can get attracted to the black band if the water level is too low. This is why you may see lower levels in breeding tanks.

Actually, Jimmy was saying that smaller bubbles would be better if the bubbles themselves are responsible for the oxygenation. And, theoretically, he is right. Smaller bubbles have much more surface area per volume of air than larger bubbles. It's an exponential surface area increase as the diameter gets smaller. However, in actual experiments, the bubbles turn out to do relatively little of the O2 diffusion into the water compared to the surface effect--which is why agitating the water surface (creating convection to the surface of underlying water) is most important and will happen with the rising water from your sponge filter whether the bubbles are smaller or larger.

Additional airstones are effectively like putting another sponge filter in as far as O2 diffusion is concerned, because they increase the convection from bottom to top about the same amount. Of course, they are very different in terms of ammonia-nitrite breakdown--they won't do that at all.

With any sort of decent agitation, and with no protein surface film from waste produects, and not an extreme bioload, the water in your tank will always be essentially saturated with O2. As all have said, warmer water will hold less O2 than colder water, so with warmer water, it is best to make sure you really do have saturation by increasing the surface agitation.

The downside to too many airstones, HOB etc. causing agitation is that you may generate very strong currents which Discus really don't like that much. Too much work to stay in one place. However, I've not actually seen any fish affected by too much current, although I'm sure it happens.

[traco]

Look at what we learn from one question!:) What Carol said about leaving space at the top so the glass top doesn't get scum. I'll be lowering my levels with tomorrow's water change. Learn something new every day. Thanks, guys!:D

[White Worm]

Thanks, very informative, just wanted to make sure I was in the right ballpark. For my 75g with 16 2.5 juvies, I was running 2 sponge filters (40g capacity each) with marineland pump (plenty of air). 2 HOB filters which did create alot of surface agitation and it was kinda funny to se the discus get pushed around a little when they swam too close but they didnt seem to care. I will soon have a new discus family in the 75g since my unfortunate problem in the past when I lost them all.
That was a very cool idea about not having to clean the top glass because mine is always dripping from the splashes and I'm sure its bacteriaville, thanks,

[JimmyL]

Just to simplify the differences between the two.
Airstone creates tinny bubbles is to increase air/water surface area to improve oxygen diffusion to water.
Sponge filter's large bubbles with the help of the riser is to create negative pressure in the center of the filter which act as an engine to suck the surrounding water through the sponge.
Just forget the theories behind it. each serves different purposes.
Jimmy

[Kindredspirit]

Look at what we learn from one question!:) What Carol said about leaving space at the top so the glass top doesn't get scum. I'll be lowering my levels with tomorrow's water change. Learn something new every day. Thanks, guys!:D


But when I do that, the water that comes out of my filters splash and the noise bugs me.....and I have turned down the flow as far as I can go and I point the end towards the tank walls....


To no avail~

Sooooooooooo, leaving space at the top helps with scum, and adds more oxygen...correct? Does more people than not do this? I wonder.......



As usual, Mikey, great thread! Barb is right in that we can learn so much other than the original topic! Ever check out how popular your last thread was and how many dif directions it took, re Fish Stores....http://smileys.smileycentral.com/cat/23/23_30_109.gif




Marie~http://smileys.smileycentral.com/cat/28/28_4_11.gif

[traco]

Dear Marie. Does the sound of your tank's in your office do this?http://smileys.smileycentral.com/cat/10/10_12_16.gif

I'm sorry but I had to use this one cuz it was a perfect opportunity (thxs, C).

Back to the real world, it sounds like some people don't use an airstone? And this helps the sponge filters work better? Do you use the plastic riser also? If it does make a difference, I'll be taking my airstones out.

[White Worm]

I think that everyone must remember,,,,,,,Please dont stop what you are doing if it works for you. Like someone said,,,,,If they are not gasping at the top of the water, then you dont have any problems.
Yeah Marie,,,, I seem to start some pretty good threads that take off for pages (especially when you, me and candy start gabbing),,,,prolly because I am not afraid to ask some stupid questions that just make me curious. I did learn alot.
In Conclusion, the more surface agitation in the tank, the better the off gas of c02 (bad stuff) and the better oxygenation (good stuff) LOL.
I love to put in simple terms just so I can understand it (I'm such the scientist huh?)

[candyl70]

Mikey,

I think its awesome that your threads take off. I learn alot from them that way, although I have to say Jimmy, that scientific explanation is pretty hard to understand!! lol!

Barb!! OMG!! Isn't he fun? I used him a few days ago...http://smileys.smileycentral.com/cat/10/10_4_4v.gif



Oh and Mike, good point about keeping to what works for you!


Candy

[Elcid]

Mike:

You should listen to Jimmy, although I don't have any airstones either (since I believe that my wet/dry provides sufficient air exchange - I might be wrong though!) , but most Asian breeders swear by the importance of the airstone in improving the growth rate of their discus. Your air pump should be more than capable of supplying air for both the sponge and an airstone, just buy a $3 valve from Walmart! I doesn't make any sense to me to test the limits of our discus, just do what others have found to work! Yea Yea, I should listen to my own advise :)

take care,
Sandeep

[White Worm]

Hey Jimmy,,,, maybe this would help us,,,,,, For instance you have empty 75g / 55g,,,, What would you put in it to make sure you had sufficient oxygenation? Plan on having (10) 2" juvies.
I have 2 sponge filters with diffusers inside each one (some say it helps with better or consistant flow through the sponge (smaller bubbles). Thats all I am running right now. The marine air pump I have, has dual output so one side of the pump goes to each filter (plenty of bubbles and surface agitation and when I lowered the water below the top of the uplift tube (you are right) still sucked water out of tube and into tank. I was running 2 sponge filters and 2 HOB's but I think this is just overkill. 50% WC every 2nd day (I know some would do more) Give me you best setup idea.
Elcid,,,, I was trying to take his advice but I wasnt sure still what exactly he thought I should have in the tank. I understood some of the theories but not the outcome.
Candy,,,, Yeah, this forum is the best invention since sliced bread or the condom.
I just think people here should always consider that these are just ideas and if something is working good for you,,,, DONT CHANGE IT. Sometimes you can add to improve but always do those things in moderation because it may not always end up to be a good thing. Discus dont seem to mind minor fluctuations in their environment but too many or too much at one time can be disaster (trust me) Mike

[JimmyL]

You've said it already. If they are flirting and chase each others, come to the glass. That the good indication whatever you're doing is just right. Don't change anything for the sake of other's idea. Each tank is different with different variables. Adjust accordingly to your own equipment and water. Discus hate changes constantly including food. They don't have taste buds like us. Putting many airstone or sponge filter doesn't mean oxygen in your tank will improve. Once the dissoved oxygen at centain temp. is saturated. It can not take on anymore oxygen molecules. With a 75gal 10/2" fish. Your fish will do well without any airstone or sponge for days. The large capacity is very forgiven to avoid any quick fluctuation of parameters. Don't do what I say and take all sponges away... I know you will not .....
Jimmy

[White Worm]

Cool Jimmy,,,, I was just trying to find out what your ideal setup would be. I just re-setup my 75g and I plan to start out with 4 juvies just so there is no problems. I just was trying to pick your brain for some good ideas,,,maybe something I hadnt thought of. Thanks, Mike

[btoday]

Two best reasons for using airstones!!!!

Better exchange of gases.
But most important for my wife, cuts down on noise.

HOW LONG DOES AVERAGE AIRSTONE LAST??????

BEST WAY TO CLEAN AIRSTONE???????

BOB