# Are airstones necessary?



## mhhauser (Feb 8, 2006)

I was searching around on some other forums, and i read a thread by a guy who had just bought a Fluval 404 or 405 for his 80gal aquarium, but what he was conserned about was getting sufficient water movement to get oxygen into the tank.

From what he said he thought that he needed a bubble wand or airstone for his tank. In most of the responses they said that you don't need one that it will get plenty of oxygen just sittting there, but also the people who replied went on to say that they have kept tanks with plants for years and never used a airstone and that they are not really that needed.

I know from reading that planted tanks need them at night because during nonlight hours plants don't photosynthisize but they do respire just like fish and animals so we turn them on at night to help get oxygen into the water.

My question is: Is that all they are used for just night hours in planted tanks?


if any of this isn't correct plz correct me i am new to this stuff and just learning.


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## Hypancistrus (Oct 28, 2004)

I regularly cause controversy and get into trouble by advocating the use of airstones 24/7 in tanks that are covered.

http://www.plantedtank.net/forums/water-parameters/18992-o2-level-measurements-ive-got-my-tank.html
http://www.plantedtank.net/forums/general-planted-tank-discussion/15068-airstones-good-bad.html
http://www.plantedtank.net/forums/equipment/21867-airstone-not.html


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## jhoetzl (Feb 7, 2005)

Well, it looks like you've done some reading so I'll just explain what I do.

Tank 1: 37g, pressurized CO2 on a controller, glass top, eheim 2026's
Never used to run an airstone, started after noticing certain fish at the surface in the mornings. To keep my co2 level where I wanted it, I run an airstone overnight only. About an hour after lights out, and stop it about an hour before lights on. Fish are happy now

Tank 2: 15g, pressurized CO2 on a solenoid (on/off with lights), glass top, Aquaclear HOB filter
No airstone - the HOB breaks the water surface enough - don't get gasping fish.

Tank 3: 6g, pressurized CO2, no solenoid, open top, Turtle 501 filter - spray bar barely pointed at water surface.
No airstone - the CO2 runs 24/7, but the spray bar is breaking the surface on open top - fish happy

Fry grow out tanks - no CO2, minimal ferts, simple mosses and floating riccia, low light - air stones 24/7, air based sponge filters and corner filters. 
Fry grow  Mosses stay alive...

To me, there is no simple yes/no answer. It depends on the setup.


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## dschmeh (Feb 5, 2006)

your going to get a diffrent answer depending on who you ask all tanks are diffrent . I dont use a airstone i put my diy co2 near my ballest and lights are on timer during the day this causes more co2 production and less at night . I never had a problem . I do know some people put a very small pump and airstone on a timer and run it at night . If you have co2 and a controller you dont need this since it comes on and off depending on ph level .


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## Keck (Jan 18, 2006)

I have an overstocked tank, DIY CO2 and very little (if any) surface movement. I run a small pump with airstone running an hour before lights out and shutting off an hour before the light come on.

Originally I did it because of my low KH and the major pH swings I had at night. Now I just run it so I know my fish get enough air at night when the plants are not oxygenating the water. However, if I had surface movement, I wouldn’t worry about it. 

The way I look at it, I get the best of everything for the price of a $5 air pump and 25 cent airstone.

1. No surface water movement during the day so my CO2 doesn’t get outgassed.
2. At night I do get surface movement and oxygen for the fish (and plants)


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## wantplantsnotwork (Nov 28, 2004)

As stated above all tanks are different. The more heavily planted/high bio load you have the more likely you will need night air. I went thru a few fish before I got around to figuring it out. Once I did, no more fish loss. 
Some day I will buy a bunch of clown loachs again.:icon_cry: 
Also, keep in mind, CO2 and O2 are two different things, a poster above infered that less CO2 at night helped. Uh uh. They do not displace each other, they are not opposites of each other, they are two different things. Too much CO2 can be a problem, but generally, if your fish are bumming in the middle of the night, it will probably be lack of O2.

And that's my O2!


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## SuRje1976 (Feb 2, 2006)

I removed my bio-wheel after my tank was fully planted so as to not gas off CO2 and compete with plants for nitrogen. After a few weeks of establishing planting and stabilizing a pressurized CO2 system, I decided to replace many of the "nutrient-depleting" plants with some that I wanted to try my hand with. In anticipation of the mail-ordered plants arriving, I removed many plants, and trimmed the ones that would remain. Mail-order didn't arrive when expected. Turns out that the decreased plant load resulted in a very large decrease in O2! CO2 remained the same, no spike in NH3, NO2 or NO3. Although I never used any type of airstone, the bio-wheel was evidently producing enough surface agitation to keep the O2 level acceptable before planting the tank. By the time the bio-wheel was removed, the heavy plant load was provinding the O2. After lightening the plant load NOTHING was providing O2! 

My wife called me at work and told me something was wrong with the fish. Immediately thought CO2 was the culprit, and told her to close the valve on the CO2 tank and turn the spraybar up. This helped a little, but when I got home, I realized that there WAS no CO2 spike (KH and pH were the same as always)! After testing the water, I added a bubble wall which releived the fish's symptoms within an hour or two. I tapered the CO2 back up and the fish were fine! 

Lost 3 japonica shrimp and almost killed 2 clown loaches and 2 flagfish. Gourami's didn't seem to affected.


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## Naja002 (Oct 12, 2005)

I read Your entire post, but I haven't read through the entire thread---So,....

I have *Needed* to use an air stone in all of my tanks that have any fish. Why? I don't know. I run them 24/7 simply because I cannot seem to find an inexpensive timer that functions properly with an air pump, and I've spent so much money recently with respect to all of this--that I am just plain reluctant to spend $25+ (x ?) on a good, reliable timer. I will in the future, but right now I just feel the need to procrastinate for a while.


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## raymond_h2002 (Feb 13, 2006)

Do the $5 timers from home depot not work for you?



Naja002 said:


> I read Your entire post, but I haven't read through the entire thread---So,....
> 
> I have *Needed* to use an air stone in all of my tanks that have any fish. Why? I don't know. I run them 24/7 simply because I cannot seem to find an inexpensive timer that functions properly with an air pump, and I've spent so much money recently with respect to all of this--that I am just plain reluctant to spend $25+ (x ?) on a good, reliable timer. I will in the future, but right now I just feel the need to procrastinate for a while.


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## Iggy (Jan 10, 2005)

I've never held with the "no surface agitation when injecting CO2 theory". 

Sure, there's plenty of O2 during the day when the plants are pearling away, but things can alter at night when demand for O2 is higher. Some of the above posts confirm this. 

I don't think it's necessarily essential to run an airstone 24/7, but if you have very little surface movement, I believe it's a good idea to run one for a period at night.


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## Keck (Jan 18, 2006)

As in my “Disaster” thread, $5 timers from home depot can go bad. I am unable to confirm that my problem was a lack o oxygen, but if it was, it was due to a faulty timer. Basically, the plastic tab that flicks the switch wore out and snapped off.


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## Naja002 (Oct 12, 2005)

> Do the $5 timers from home depot not work for you?


If they are mechanical--I won't use them. Way too many problems years ago, so I only use digital. Yet nowadays there are so many cheap (quality-wise) digital timers out there its pathetic.

Some other members here directed me to the $8-9 digital timers by Timex at Walmart, Target, etc--they are working great for lights and keep time very well--but for some reason they go blank--completely--when used with an air-pump. Both of them. Then I have to unscrew the back and reset them--which I had to figure out how to do by shorting it while its plugged in....:icon_eek: 

I started a post about timers about a month ago here:

Timers....?


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## wapfish (Oct 14, 2005)

This question sure gets tossed around a lot :smile: .

I dug out some dissolved oxygen (DO) numbers for my 29g jungle tank that can provide a bit of numerical perspective. The tank has pressurized CO2 with no surface agitation, good internal flow, low pollution, and is moderately overstocked. It’s covered by a glass partition such that there’s a 1/2” strip in front and 3/4” strip in back open to the atmosphere. I run it a bit cool, at 72F => saturated DO ~8.7ppm .

*4wpg lighting*
a) morning ppm 6.6 
evening ppm 13.7
next morning ppm 6.6 (no overnight aeration)

b) morning ppm 7.4	
evening ppm 13.0 
next morning ppm 8.2 (continuous high level overnight aeration)

c) morning ppm 8.2	
evening ppm 14.8 
next morning ppm 7.8 (continuous modest overnight aeration)

*2wpg lighting*
d) morning ppm 4.1 
evening ppm 6.9
next morning ppm 4.1 (no overnight aeration)

It's obvious that when photosynthesis is really kicking during the day (a,b,c), DO is high the next morning. It’s significantly higher if overnight aeration is provided however. Under conditions of low light reduced photosynthesis during the day (d) DO is quite low the next morning. If the tank were even more overstocked, more polluted, or covered, DO would be even lower under low light, possibly approaching dangerous levels for the fish. DO concentrations of 5-6 ppm are generally recommended for good fish health with saturation levels possibly even better. Fish are severely stressed at <2-3ppm and will die at <1ppm (http://www.automatedaquariums.com/tecdo_3.htm; http://www.vcnet.com/koi_net/do.html). 

While every tank is different, it seems to me there's practically no downside to running an airstone at night and a lot of potential upside:
1) it helps the tank stay clean by facilitating decomposition of dissolved organics and ammonia scavenging (more oxygen is better for the biofilter)
2) it keeps the fish healthy and happy without having to worry about photosynthesis levels
3) it keeps the surface free of scum (a problem for folks with hard water)
4) pearling starts earlier the next day (if you like pearling :smile: )

The only significant problem I can see is for folks with using CO2 in tanks with low KH. In that situation, vigorous and prolonged overnight aeration could cause sufficient CO2 outgassing to result in a substantial pH change. It would also represent a significant wastage for DIY CO2 systems. It would probablay be wise to restrict aeration to just a few hours in such cases. For moderate-high KH tanks, outgassing/CO2 loss really isn’t a problem.


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## Iggy (Jan 10, 2005)

That's an interesting post Wapfish.

Obviously all tanks are different, but it's good to see some actual figures relating to DO levels.:thumbsup:


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## fresh_lynny (Mar 9, 2006)

Wapfish...good info. Thanks for the post


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## standoyo (Nov 6, 2005)

great post wapfish. more reason to keep using overnight aeration.


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## fresh_lynny (Mar 9, 2006)

All that said, can anyone recommend the best air bubbler/system to get? I am still in the set up phase.
Thanks~


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## wapfish (Oct 14, 2005)

fresh_newby said:


> All that said, can anyone recommend the best air bubbler/system to get? I am still in the set up phase.
> Thanks~


Not critical. Smaller bubbles are better. Limewood diffusers are good. I use Sweetwater AS10 http://www.aquaticeco.com/index.cfm/fuseaction/product.detail/iid/9751/cid/2328
with a Rena pump. Most anything you get at a LFS should work. Just keep track of your pH/CO2.


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## Keck (Jan 18, 2006)

I use a $4 pump from Wal-Mart and limewod diffusers that I had from an old protein skimmer.

Originally I used an oscillating powerhead pointed at the surface, but it was too strong for my 29g tank.


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## banderbe (Oct 10, 2005)

mhhauser said:


> I was searching around on some other forums, and i read a thread by a guy who had just bought a Fluval 404 or 405 for his 80gal aquarium, but what he was conserned about was getting sufficient water movement to get oxygen into the tank.
> 
> From what he said he thought that he needed a bubble wand or airstone for his tank. In most of the responses they said that you don't need one that it will get plenty of oxygen just sittting there, but also the people who replied went on to say that they have kept tanks with plants for years and never used a airstone and that they are not really that needed.
> 
> ...


I run airstone for about 8 hours after lights out. If I don't fish are at the surface by morning.


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