Oxygen (Air Pump) To Much A Bad Thing ?

Hey All,

Brought a big air pump, and ran a spounge filter and a extra air stone in my tanks for extra oxygen and hopefully a little cleaner.

Is it a bad thing to have to much air/oxygen in the tank ?

Cause the top of the water in each tank its all bubbling/moving which i think is pretty cool cause now there more than enough air flowing through - but just want to know if its all safe ?

Im guessing it will be okay/safe, but is there any bad points ? or all good ?

Thanks

i use a diffuser and or airstone in each tank. Evaporation is a bit more but otherwise I see no problem. cheers jk :thumbup:

What is the difference between an air-stone and a diffuser?

MiT said:

What is the difference between an air-stone and a diffuser?

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A diffuser fits on the output port on your filter mixing air with the water being expelled ( such as you would see on most power heads) and an air stone simply puts air bubbles into your water column.

look at the web page and scroll down to diffusser http://www.eheim.com/products/detail/23/category
The good news is, if does indeed fit at the out valve of your external filter but uses no additional power like and airstone. cheers jk :thumbup:

Hi all,
For those new to the site, we have an article that covers this area in some detail:
"Aeration and dissolved oxygen in the aquarium" - <http://plecoplanet.com/?page_id=829>

But as a reply to the direct question.

Brought a big air pump, and ran a sponge filter and a extra air stone in my tanks for extra oxygen and hopefully a little cleaner. Is it a bad thing to have to much air/oxygen in the tank ?

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You can never have too much oxygen (or biological filtration capacity).

Cause the top of the water in each tank its all bubbling / moving

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That is what you want, it is the increased surface area for gas exchange that raises the oxygen content of the water (and out-gases CO2). One reason venturi diffusers (Like Bigbird's Eheim one) are good is that you can create very fine bubbles, with a long residence time in the water column and it is only the really fine bubbles that contribute much O2 to the water directly. The air pump itself won't actually add much oxygen directly, because air is only ~ 20% O2, and oxygen isn't very soluble in water, meaning the bubbles are lost at the water surface before much O2 can diffuse from them.

Our tanks are nearly always poorer in oxygen than the fishes natural habitats. If you think of a fast flowing river, all the "white water" is white because the air bubbles trapped in it, and if you have plants "pearling" whilst photosynthesising, that is because the water is 100% saturated with O2 and no more can go into solution. It then out gases as the O2 "pearl" bubbles.

Even if you keep planted tanks, unless you are adding CO2, more gas diffusion will actually make CO2 more available rather than less, and there is no reason not to have "wet and dry" trickle filters, air pumps etc.

cheers Darrel

Thanks All,

The reason why i asked is cause i heard (dunno if its true or not) that if you had alot of air (airstone/diffuser) that you PH will drop heaps every now and then ???? Like i said i heard that from actually a few people but dunno if its true or not .

Hi all,

The reason why i asked is cause i heard (dunno if its true or not) that if you had alot of air (airstone/diffuser) that you PH will drop heaps every now and then ???? Like i said i heard that from actually a few people but dunno if its true or not

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Having extremely efficient aeration should keep your pH more stable and possibly be higher than without it. This is pH effect is dependent upon the carbonate buffering in the water.

In water without much carbonate buffering (below 4dKH), CO2 build up from plants and animals respiring at night and this will lead to the pH going down as some of the CO2 will go into solution as carbonic acid. When you have more buffering this doesn't happen due to the carbonate ~ carbonic acid equilibrium.

Photosynthesising plants both add O2 and remove CO2, meaning the pH will rise, unless the water is all ready heavily pH buffered by carbonates (in this case the pH will remain at about pH7.8 what ever you do). In water with little buffering the pH can swing about from pH4 up to pH8 as the CO2 level rises and falls.

In water with little carbonate buffering, lots of aeration drives off CO2 and you don't get these big pH swings. In buffered water it doesn't make any difference. Biological filtration is a big user of both oxygen and carbonates, which is a reason for both having some buffering and lots of oxygen.

cheers Darrel