Aeration in a planted aquarium

[Art]

As we all know, plants breathe and need oxygen. Low oxygen levels can be a problem in a planted aquarium. For us, usually that happens overnight when the plants are not photosynthesizing.

Think about it. Your fish, plants and bacterial colony are all taking up oxygen at night. It will go down and it's been known to go down too much if you have a heavy fish load with plenty of plants.

To compensate, some people recommend/use an air stone at night. In fact, Aqua Design Amano uses this design where their CO2 timer turns on an air stone overnight.

Following one of our own, I run an air stone for 5 minutes every hour. I've had good success with that and it doesn't impact CO2 levels in the tank.

What are your thoughts / experience with aeration? Needed, not needed, myth?

 

[Immortal1]

I would not be without air stone(s) in my tanks.

 

[JPog]

I've personally never used an air stone in any planted tank. I haven't noticed an issue with the plants. Full disclosure my tanks usually aren't fish-heavy so I don't have that concern. My tanks are also all open-top, so don't know if that has a positive effect on Oxygen exchange.

 

[GreggZ]

You want to have both good oxygen levels and good CO2 levels. They are not mutually exclusive.

This doesn't necessarily mean an air stone, it can also be achieved with good surface agitation.

Personally I do both. My spray bars are angled up to the surface and provide a constant surface ripple, which creates oxygen. I also have a powerful air pump. I run it ten minutes out of every hour that the CO2 is on. Then I run it for an hour after CO2 turns off as well.

It does two things. It provides a nice blast of surface agitation that creates oxygen, which my Bows appreciate. It also creates a lot of flow. The pattern is across the top of the tank, down the front glass, then it sweeps across the substrate. This pushes any detritus the rear of the tank, and keeps the front substrate very clean.

 

[Aquascape_SG]

Sump run tanks like mine don't have to worry about this issue. There's more than enough oxygen.

 

[Burr740]

Big fan of aeration. Whenever Ive ran airstones everything just seemed cleaner and healthier. My canisters all have skimmers which do a pretty good job. If not for that Id definitely use air stones

 

[JPog]

I'm so anti-equipment that I never run airstones, skimmers, powerheads etc. I don't even like the sponge prefilter I put on my lily pipe to prevent shrimp from getting sucked up. Anyone think there is increased O2 exchange with open-tops? Obviously air gets everywhere, but wondering if the motion of surface agitation, brings more air in, or is this just wishful thinking, LOL.

 

[Joel Armstrong]

You want to have both good oxygen levels and good CO2 levels. They are not mutually exclusive.

This doesn't necessarily mean an air stone, it can also be achieved with good surface agitation.

Personally I do both. My spray bars are angled up to the surface and provide a constant surface ripple, which creates oxygen. I also have a powerful air pump. I run it ten minutes out of every hour that the CO2 is on. Then I run it for an hour after CO2 turns off as well.

It does two things. It provides a nice blast of surface agitation that creates oxygen, which my Bows appreciate. It also creates a lot of flow. The pattern is across the top of the tank, down the front glass, then it sweeps across the substrate. This pushes any detritus the rear of the tank, and keeps the front substrate very clean.

Hi Gregg,

Does your American Pinpoint pH controller activate your air pump, or do you have the air pump controlled by another device/timer?

Cheers

 

[Art]

I'm so anti-equipment that I never run airstones, skimmers, powerheads etc. I don't even like the sponge prefilter I put on my lily pipe to prevent shrimp from getting sucked up. Anyone think there is increased O2 exchange with open-tops? Obviously air gets everywhere, but wondering if the motion of surface agitation, brings more air in, or is this just wishful thinking, LOL.

In all of my reading, yes, surface agitation does improve gas exchange. This is a big topic on the reefing side. How much and how quickly, I don't know.

All I know is that at times when I was heavily planted and heavily stocked with fish, my fish would gasp at the water surface. Since adding the automated aeration, I haven't observed this behavior. In theory, at least, it also makes me feel calmer that O2 isn't low.

 

[GreggZ]

Hi Gregg,

Does your American Pinpoint pH controller activate your air pump, or do you have the air pump controlled by another device/timer?

Cheers

 

[GreggZ]

Hi Gregg,

Does your American Pinpoint pH controller activate your air pump, or do you have the air pump controlled by another device/timer?

Cheers

I control the air stones from a smart power strip timer. I could run it off of the controller as well. I doubt it makes much difference either way. Come to think of it maybe I will run it that way for a bit just to see if I notice anything at all.

 

[JuJuFish]

How important would the air stone be in a low tech tank that isn’t running CO2? And has good surface agitation from a spraybar?

 

[GreggZ]

How important would the air stone be in a low tech tank that isn’t running CO2? And has good surface agitation from a spraybar?

Good surface agitation is the basically the same as running a small air stone. Keep in mind it's not the bubbles that create oxygen, it's the bubbles breaking the surface tension that creates oxygen.

So as long you have good surface agitation no real need for an air stone in a non CO2 tank.

That being said in my heavily CO2 injected tank I do run powerful bubbles at intervals throughout the day to create extra oxygen in the system. It allows me to keep my CO2 levels higher without having a negative effect on the Rainbows.

 

[Art]

It allows me to keep my CO2 levels higher without having a negative effect on the Rainbows.

This is why I do the same thing. I've noticed I can keep a 1.5 - 1.6 pH drop without my fish or snails being negatively impacted.

 

[Pepere]

All of my pressure co2 tanks have lids on them and canister filters with spray bars that agitate the surface.

They all have ziss no clog airstones as well.

with the lid on the tank and co2 being pumped in, the co2 levels between the water and the lid is going to rise. Running an airstone pumps a constant supply of air under the lid.

The idea of minimizing surface agitation to reduce CO2 use while intuitive in essence forces you to run low co2 bubble counts so you dont inadvertently gas your fish by the end of the day. The relative lack of gas exchange coupled with low injection rate means it takes much longer to reach equilibrium between injection and gas exchange so you might run several hours with sub optimum co2 levels in the tank.

I have 2, 29 gallon display tanks and a 20 high that I run at around 30 ppm co2 and a 5 lb tank gives me 6 weeks of use. A single 3 watt air pump handles all three tanks.

How does this compare to other peoples co2 consumption?

Personally I would rather spend extra on CO2 and electricity and not subject my fish to low O2 levels. They have no say in regards to swimming in my tanks, so I err on the side of caution.

 

[HardeeParty]

I’ve wondered about this, and tried multiple options. I run two tanks without lids. Both now have surface skimmers. Both have canister filters with the outlet near the top creating surface agitation. I used to have a really hard time with oil/scum buildup from surface tension, but since I’ve installed skimmers they surface remains clear. Until this point I ran a bubble stone in both tanks, but have transitioned to PM only, then completely off (it splatters and creates hard mineral buildup everywhere). There’s no observable difference in fish behavior before or after. I feel that with such small tanks the outlets creating surface ripples is achieving enough gas exchange. Does this sound like a reasonable conclusion?

 

[Pepere]

Does this sound like a reasonable conclusion?

Without lids, I would be comfortable not using an airstone. Surface agitation and skimmer would be fine.

do I have proof that co2 levels build in the area between the water and the lid to be a problem? Nope. I have no proof… just a concern.

I understand the annoyance of bubbles popping. I do find I need to clean the lid weekly with the sponge filter bubbles.

I also like having wall hung double sponge air driven filters so Ihave a fully cycled filter I can put in a quarantine tank after running quarantine meds for a week, and water changing and using carbon to adsorb the meds.

 

[GreggZ]

I have 2, 29 gallon display tanks and a 20 high that I run at around 30 ppm co2 and a 5 lb tank gives me 6 weeks of use. A single 3 watt air pump handles all three tanks.

How does this compare to other peoples co2 consumption?

So about 80 gallons and 5 lb tank last 6 weeks. Sounds like it's in the right ballpark. I go through a 10 lb tank on my 120G about every 14 weeks.

I’ve wondered about this, and tried multiple options. I run two tanks without lids. Both now have surface skimmers. Both have canister filters with the outlet near the top creating surface agitation. I used to have a really hard time with oil/scum buildup from surface tension, but since I’ve installed skimmers they surface remains clear. Until this point I ran a bubble stone in both tanks, but have transitioned to PM only, then completely off (it splatters and creates hard mineral buildup everywhere). There’s no observable difference in fish behavior before or after. I feel that with such small tanks the outlets creating surface ripples is achieving enough gas exchange. Does this sound like a reasonable conclusion?

If it ain't broke don't fix it. Your surface agitation is likely creating enough oxygen. But since we don't test for oxygen it's very hard to say with any certainty. I know in my tank some extra blasts of O2 via vigorous bubbles seems to make the tank run smoother. But every tank is different. Only real way is to run it one way for awhile, then the other and observe.

 

[Count Krunk]

On a tank with a sump is running airstones at some interval required? I was thinking to run it for an hour or two post co2 to make sure the water degasses.

This would be a 135g display with a 40b sump, mesh top on the display nothing on the sump.

 

[Kevin Lee]

I'm so anti-equipment that I never run airstones, skimmers, powerheads etc. I don't even like the sponge prefilter I put on my lily pipe to prevent shrimp from getting sucked up. Anyone think there is increased O2 exchange with open-tops? Obviously air gets everywhere, but wondering if the motion of surface agitation, brings more air in, or is this just wishful thinking, LOL.

I was wondering the same thing, I don’t use o2 but I have a pretty heavily planted 55g and I just bought a wave maker and added it half way up the side of my tank and have it pointing up to the surface hoping it will agitate surface tension and be helpful to my plants?