Oxygenation Of The Water.....

[ATK!!!]

To be quite honest, your rio 180 shouldnt suffer any oxygenation problems its usually only a problem with small tanks and breeding tanks, which can be overcome with air pump filters agitating the surface.

biOrb tanks for example are a good example, especially the rounded ones which hav a very small surface area when full up, or the fluval edge with a very small square gap. In which case people usually advise you to stop filling it up an inch below the top glass.

Very true, Biorbs and such have a pretty rubbish surface area and therefore not much of an area to transfer gases. That's probably another reason why they put an air pump in them but IMO that doesn't really help and just makes the filter too weak, seeing as its only powered by air. Surely a heavily planted tank will be giving off a reasonable amount of oxygen during the day, or would the plants have had to take it in in the first place? (Photosynthesis isn't my best subject!)

The rio 180 has a surface area of 45.45cm2 and a depth of 50cm, compared to taller tank it has a reasonable surface area so you shouldn't experience a problem.

 

[Smells a bit fishy]

Plants use up CO2 during the day and give out oxygen, however at night it's the opposite. So if you have a heavily planted tank, it will be nights that would be worrying if there isn't enough oxygen. But I don't know exactly how much oxygen they use up or how much CO2 they give out.

 

[StandbySetting]

Plants respire all the time, so they are constantly producing CO2.

 

[saz326]

Plants respire all the time, so they are constantly producing CO2.

Very true.

They are a bit like people. They breathe all the time but do most of thier eating during the day. During daylight hours they photosynthesise taking in carbon dioxide and releasing oxygen - so during daylight they give out more oxygen than they take in to breathe.

 

[fishguy2727]

Air bubbles will increase aeration. This is a common way of aeration in other industries but this hobby somehow is stuck on the idea that it is worthless. Commercial ponds, even hobbyist ponds, water sanitation, etc. all urilize the very powerful aeration effects of bubble aeration.

I think some of this is over analyzing. The surface area doesn't allow more pressure, it is simply surface area for the opportunity of gas exchange. The only way pressure has anything to do with it is altitude, and even that is insignificant for a hobbyist. A tank with a small surface area is under the same pressure fromt he air as one with a lot of surface area. Although there would be a difference in the oxygen carrying capacity of three tanks (one at sea level, one at 10,000ft, and one at 20,000ft) this is obviously insignificant in the hobby.

There are three main things that effect aeration in our tanks: surface area (all of it, including bubbles, not jut at the actual surface), surface agitation (all of it, including in filters, not just the actual tank surface), and temperature. Tempereature greatly effects how much oxygen the water can hold. Combined these three things will dictate the oxygen levels available in your tank (minus what the fish use).

To really answer your question: any time water and air interact gas exchange takes place via diffusion. There is a lot more oxygen in the air than in the water. At ANY air-water surface (tank's surface, and air bubble, inside a protein skimmer, etc.) this exchange happens extremely quickly. Oxygen doesn't know or care if the air-water surface is at the tank's surface, inside a bubble, etc., it diffuses. CO2 also leaves the water at these surfaces, this is why people with planted tanks who add CO2 won't run air stones or may not even have a HOB filter.

 

[Geoff-]

air bubblers help aeration because the rising torrent of air bubbles draws water up with it. therefore you get continual water exchange at the surface which is where most oxygenation takes place. the water then descends elsewhere forming a "loop" current in the tank so you have continual surface water replacement and the oxygenated surface water being drawn down into the tank.

 

[Shaddex]

 

[raptorrex]

air bubblers help aeration because the rising torrent of air bubbles draws water up with it. therefore you get continual water exchange at the surface which is where most oxygenation takes place. the water then descends elsewhere forming a "loop" current in the tank so you have continual surface water replacement and the oxygenated surface water being drawn down into the tank.

even 1x turnover will be enough to far exceed any current added by an air stone.

as mentioned plants respire at all times. but only during daylight do they produce high O2. during the day plants are net O2 producers and net CO2 reducers. during the night plants are net CO2 producers. and no O2 is produced.

 

[fishguy2727]

Not necessarily, air stones can create a massive current, like pointing a strong powerhead at the surface from the bottom of the tank. A very weak air stone, yes, will create a pretty mild current, but a strong air stone can create a strong current, expecially with large bubbles (large bubbles create more current).

 

[raptorrex]

Not necessarily, air stones can create a massive current, like pointing a strong powerhead at the surface from the bottom of the tank. A very weak air stone, yes, will create a pretty mild current, but a strong air stone can create a strong current, expecially with large bubbles (large bubbles create more current).

we will have to disagree on that. it creates a current, but nothing like that of, even, a weak filter.

 

[fishguy2727]

It is not an opinion, it is fact. Large bubbles create a strong current. At the National Zoo that had a massive air stone running in their ray tank and it created a 2" swell, that is a lot of current. I have seen multiple tanks with strong air stones that now have multiple times the flow they had with just filters. My 75 has more current created by the air stones than by the two Fluval 405s. The good thing about air stones is that the current created is is wide, like Koralia powerheads, not just a small jet of water that can be quickly dissipated.

 

[StandbySetting]

Agree with fishguy here, it all depends on the size of the bubbles, larger bubbles will ascend with a higher velocity, but the standard aquarium pumps and air stones simply aren't as good as the flow provided by a filter, on a pond maybe so, but in most cases the rising bubbles wont do that much.

 

[raptorrex]

It is not an opinion, it is fact. Large bubbles create a strong current. At the National Zoo that had a massive air stone running in their ray tank and it created a 2" swell, that is a lot of current. I have seen multiple tanks with strong air stones that now have multiple times the flow they had with just filters. My 75 has more current created by the air stones than by the two Fluval 405s. The good thing about air stones is that the current created is is wide, like Koralia powerheads, not just a small jet of water that can be quickly dissipated.

we are talking hobby gear here, not commercial. on hobby gear the current is not in the least significant. especially if you consider. on the whole, hobby pumps get not much bigger than 600 lph ( as off the self sale items), so you can have bigger bubbles, just not enough of them to cause a significant current. as my tank has a flow (real not box claim) of over 1000lph. the flow that creates is far higher, therefore the predominant flow in the tank.

your comment IS an opinion, and nothing more. i just disagree is all. if that causes you problems, deal with it.

 

[Tizer]

zomgz attitude <3

 

[fishguy2727]

My 75 has two hobby grade pumps and they create a significant amount of flow, but I guess direct observation is just opinion. Maybe you haven't used the right air pumps?