# Bubbler or not?



## Sam66 (10 Feb 2022)

Basically in a low tech tank should I be running a bubbler?

Options I have are:
Air driven sponge filter - large bubbles
Skimmer with Venturi - adjustable but lots of tiny bubbles
Basic air stone

If it is a good idea then how long should I run it for, and during lights on or off?

I was initially running the filter with a spraybar which was providing good surface movement but kept submerging my few floating plants.  I also got some surface film/scum so added the sponge filter which resolved it, but this was later removed for use in a shrimp tank.

I have now directed the spraybar down a bit so floating plants are happier.  I also added the skimmer below the surface (so not actually skimming) to provide more flow at the rear of the tank.

Bubbles do seem to help move the surface around but I don't know if they are beneficial overall.

120l Juwel lido 61cm x 41cm x 58cm
Set up about 5 weeks ago.  External cannister filter.
2x original T5 tubes, one with reflector angling the light away so not full brightness.
Fine sand/gravel over soil
Dosing 10ml TNC complete per week
Lights currently on for 6.5 hours with very little additional natural light.
No CO2
No livestock other than snails

Cryptocoryne wendtii green
Hygrophila corymbosa Thailand
Anubis's heterophylla
Microsorum pteropus
Unknown stems
Unknown swords
Unknown moss
Salvinia minima


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## plantnoobdude (10 Feb 2022)

I see no reason not to! I would run the basic air stone because of aesthetic reasons if it were my tank, but other than that, any of those options should be fine.


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## Sam66 (10 Feb 2022)

plantnoobdude said:


> I see no reason not to! I would run the basic air stone because of aesthetic reasons if it were my tank, but other than that, any of those options should be fine.


Running 24/7 or just when the lights are on/off ?


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## arcturus (10 Feb 2022)

Sam66 said:


> Running 24/7 or just when the lights are on/off ?


That depends on the density of plants but it seems you have plenty of plants based on your list. In this case, there should be plenty of dissolved oxygen in the water during photosynthesis. If you have good water circulation, you probably don't need the bubbler and the extra gaseous exchange. But while the lights are off, plant respiration will reduce oxygen concentration. This is when the extra bubbles would be useful. If you decide to keep the tank with snails only, then skip the bubbler


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## dw1305 (10 Feb 2022)

Hi all, 


Sam66 said:


> Skimmer with Venturi - adjustable but lots of tiny bubbles


I like <"a venturi">.  

cheers Darrel


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## Jaseon (10 Feb 2022)

Is it true any  CO2 exchange happen at the surface when the bubbles burst, and not in the water column?


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## arcturus (16 Feb 2022)

Jaseon said:


> Is it true any  CO2 exchange happen at the surface when the bubbles burst, and not in the water column?


Gaseous exchange mostly takes place between the water surface and atmospheric air. Surface agitation (ripples) increase the total area of the water in contact with the air. Gaseous exchange can be further increased if the surface tension of the water is broken, which is is the main role of the bubbles coming out of the air stone (they also help circulating the water, which is needed to distribute the gases). There should also be a minor amount of exchange inside the tank, since some of the gases injected through the air stone can dissolve in the water. But this will only happen with very small bubbles, which are not what an air stone produces.


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## hypnogogia (16 Feb 2022)

Venturi might be better.  Ive found that airstones can increase the amount of suspended gunk in the tank.


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