# Bubbles at night



## Fishguy10 (Aug 6, 2011)

I've been wondering, do I need to have an air pump running at night? I read that having bubbles at night helps prevent large Ph swings between night and day, but I've also heard that not many people actually do this. 

Right now I have a pump, but there are so many bubbles when I turn it on that the gravel is blown around if I put the air stone under the gravel at all. I have a hang-on-back power filter (I know that it's not ideal, but I already had it, it works well, and it fits better in the location than a canister filter would) and I was wondering if that would be enough aeration. 

I will be getting CO2 up and running very soon so I figured that I better find out what to do. Luckily the filter (emperor 280) does not cause too much surface agitation except for the area immediately under the output. By the way, not sure if it matters too much, but the tank is a 29 gallon. So, What do you think? Do I need bubbles at night or do you think my fish would be ok without aeration? Thanks in advance.


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## OVT (Aug 26, 2010)

If you ask 3 people this question, you will get 5 opinions. My answer is: it depends and maybe . The primary reason for having an airstone is to increase the amount of oxygenated water, not to control the Ph.

The theory goes that the bubbles from an airstone agitate the water's surface and, therefore, affect the gas exchange in the tank: CO2 is expelled and O2 is absorbed. (Lowering the % of dissolved CO2 raises the Ph). Your water temperature also has a direct effect: the higher the temp, the less O2 it can absorb. 

Let's assume the theory is correct. Then the question becomes: why would we want more O2 in the tank at night? So that the fish does not suffocate, the answer goes. While plants produce O2 during the day as a by-product of photosynthesis, they also consume O2 and produce CO2 at night.

One variable is what is your stocking level: the more fish you have and the more plants you have the greater is the demand for O2 at night.

Another variable is what type of fish you have: some fish require higher O2-nated water then others and some fish species can utilize atmospheric O2.

Another variable is how much of water agitation do you normally have 24x7. What happens when your filter's flow decreases over time?

A lot of people argue (and I agree) that in a "well balanced" tank there is no need to run an airstone at night. Well, balancing a tank might be easier said then done in practice. I personally have at least 1 overstocked tank and I personally lost a very valuable Discus to suffocation because of my (temporary ) stupidity.

So, while my answers to your question are "it depends" and "maybe", I personally see very little downside and and very high potential upside to running the bubbles at night.


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## Fishguy10 (Aug 6, 2011)

Thank you for the reply, I think that that pretty much sums up the entire argument. 

The only problem that I have with the air stone is that it gets in the way and is one more thing I have to add to the tank. I would have to be able to hide it pretty well, otherwise I think that it would somewhat ruin the overall look of the tank with a big hose going down to a blue stone right in the middle of the tank. 

Other than aesthetics, I don't see any major reason not to have one. I don't think that it could hurt anything. My only other concern would be possibly splashing water up onto my light which would then either cause spots, algae, or some kind of light-blocking residue. That's sort of why I wanted it in the middle, my filter would prevent the bubbles from splashing water onto my light, it would just splash under my filter instead. Can you think of any way to prevent splashing so I can move my air stone to a more discrete spot?


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## OVT (Aug 26, 2010)

I agree that splashing can be an issue. I'd probably go with an adjustable air pump so that you can control how high the splash goes. What I did in one of my tanks was to use a heavy bubble wand along the back wall and hid the black air line behind the intake: not visible against the black background. The wand also has many holes and produces small to medium bubbles, not much spray. I've had it for 8+ years and maybe cleaned it from algae 3-4 times. It is also fun to watch the fish playing in the stream 

The wand is flexible and I've seen people make a circle out of it and put it in center or so with the airline routed under the substrate. You can now even get wands with built-in LEDs. Just use your imagination and your taste


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## Fishguy10 (Aug 6, 2011)

Smaller bubbles would probably be better just because they wouldn't cause as much splashing as big bubbles. Do you think that I could put the air stone in the filter itself, not the intake but the actual filter body, and bubble it there, or would that pretty much be pointless?


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## OVT (Aug 26, 2010)

I did have a air stone in a sump filter and that worked fine: oxyginated water would get pumped into the main tank. One potential issue I see is whether the filter's pump would choke on the air, that's one reason why people stopped pumping CO2 into canister filters. I also forgot to mention that you can also use in-line air flow valve with your tubing, cheap plastic gizmo < $1.

In the end, as I have alluded in my long post, do experiment. That's part of the fun of this hobby, every tank is different, and that's how we learn.

Happy fishing


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## Fishguy10 (Aug 6, 2011)

Thanks for the information, I'll experiment with it. Maybe try it without any bubble and see if there is any downside/Ph swing and go from there. If there is, I might as well try pumping air into the filter body itself, not the part with the impeller, the container part right after that. If all else fails, I guess I'll find a way to hide the airs stone and prevent splashing. Thanks again.


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## Do78521 (Dec 15, 2006)

I know I am a little late on this thread. but I was wondering the same thing. But I have a dilemma hopefully you can help me answer. Sorry I kinda jacked your thread. what about tank that doesnt have any livestock. Is it ok to leave Co2 on at night or is that a waste since photosynthesis occur during the day (when lights is on). And also if you run a pressurized co2 system with a solenoid on a timer and when its off, does the solenoid completely shut off your co2 tank completely? with no co2 goes to waste. assuming theres no leaks with your regulator???? eventhough the main valve on your co2 tank is open and the needle valve remain open.. or is it better to just turn the whole system off?


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## Mr. Fish (Oct 24, 2007)

It would be a good idea if you had Co2 running during the day.. but at this point you don't have much of Co2 in that tank to worry about and can use all that's possible.

Plants will only consume it during photosynthesis periods but will take you even longer to build it up if you take it all out at night. Now if you had injected co2 running that's a different story, an air-stone would be healthy for your fish.


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## Do78521 (Dec 15, 2006)

so I should leave it on 24/7 so i dont have to restart the co2 cycle in my water column.... just make sure im getting it. Thanks fish guy


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## Mr. Fish (Oct 24, 2007)

I'm not sure I understand.

You shouldn't run it at all if you're not running Co2 @ night. You need all the natural Co2 you can get at the moment... Your HOB will give your tank enough aeration at the moment.

Once you start injecting co2 thats when I'd use the airstone at night, but its not really needed.


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## corsair75 (Dec 21, 2011)

The HOB does a great job of breaking the surface tension, so air stones are probably not a huge deal. With canister filers that move lots of water with a silky smooth surface, its a more critical thing. It mattered when I lived in Norcal and had soft water. At that time I had to aerate at night to keep the pH close to daytime levels. Now I live in Texas with heavily buffered water you could drop in a cup of coffee into and not acidify it, so it doesn't matter.

I'm agreeing with it depends and maybe.

As for aesthetics, airstones come in a million shapes and varieties and they all work fine. Even a bubbling pirate chest. Let your heart be your guide. You can get artsy with it you want. This picture is many years old, but there was a disc airstone in the offering plate of the idol at center, and a 4' curtain of air in the back. Kicked on an hour before lights out. If it has to be done it can be made to look good.


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## The Trigger (Apr 23, 2012)

If you do decide to add one hook it up to a timer and set it to come on after lights and co2 shut off. I used to do it and it never caused a problem. I stopped once I got a canister filter with a spraybar and that does basicly the same thing which is good surface aggitation for surface oxygen exchange. So like the origional guy said its more an matter of preference. Just don't run it in the day. the bubbles from the air pump will cause too much loss of co2 when they break at the surface


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## Tot3nkampf (May 10, 2012)

i have done this both ways but my planted tanks are pretty well stocked so o2 or at least surface agitation at night will help the fish and the plants. you will notice that amano runs airstones at night on his tanks now. of course this does drive off more co2 and causes a pH swing unless you are using a pH controller with your setup. do they fight against one another? yes. is it able to stay pretty balanced in spite of this and considering that i also buffer the water with both acid and alky buffer? yes it does. 

as for the OP, i never had good use of co2 injection in any system containing a biowheel. now i love biowheels for non co2 tanks, but thinking that they dont drive off much co2 due to limited surface agitation is erroneous. the spraybar over the wheel is in effect a wet/dry system. there is tons of o2/co2 exchange going on here. if you must use a biowheel than you may consider using excel for your carbon needs.


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