Airstone in plants tank needed?
- Thread starter M00n3at3r
- Start date
It really depends on fish size & numbers. In a Walstad method tank there is no filtration or surface agitation but very light stocking.
Glabe and Freshy, you two are nuts! (in the nicest kind of way) M00n, these two will sell you their "No fishing" signs... gotta watch em!
Snails will typically move to the top of the glass and hang out there when O2 is low. Detritus worms will do the same. "Lightly planted" is usually not a very balanced tank. Agitating the surface to create CO2/O2 exchange is all that an airstone really does. Your filter does the same and is usually enough unless yours pumps water in the tank below the water's surface. Airstones do not inject oxygen into the tank's water. Simply, the bubbles are too big. Running one 24/7 can actually deplete the CO2 in the tank thus messing up the pH and hurting the plants and other inhabitants.
Airstones are like ice cream cones, they are fun to have, but no one really needs them. ... and too much can jack you up!
I have the no fishing sign already!
I would totally put one of the bubble chests in though. All of my filter outputs are underwater, but I can angle them to point up. 
The first is my 75g, the second and third are my 29g. The 29 is still in progress.
Agreed! That's why I said that. Pumping water in below the water's surface doesn't really make sense, but if you did, an airstone or power head would be your only hope.
Edit: I just saw your photos M00n... You need some surface agitation for sure as Mark said. I wouldn't have dreamed this would be your setup haha! It's fine, just agitate that surface some or Mark's musings will be true. (X<
Byron Amazonas
AC Members
The issue of surface agitation and water movement in planted tanks can be daunting. One can read authors that advocate none to those that insist on some, and both sides saying for much the same reasons.
Some surface disturbance likely won't have much effect on the plants. However, we are talking natural or low-tech setups here. A high-tech planted tank with diffused CO2 is a different thing. My comments will be with respect to low-tech, meaning no artificial CO2 addition.
For years, all planted tank writers advocated no excessive surface disturbance (airstones, bubblers, surface movement) because it drove off CO2. A couple years ago, some writers changed, and began advocating the opposite. I was part of an extensive exchange of data on this issue on one of the specialist plant forums with people like Tom Barr. To date, there are no accurate scientific studies to prove this new viewpoint, so any benefit is not assured. There is plenty of evidence to prove that CO2 is driven off faster. This is important because the dissolved CO2 in the aquarium has to be higher per volume than in the air in order to provide sufficient carbon for the plants. CO2 is produced by respiration of fish, plants and bacteria as others mentioned; but the greatest source is in the substrate, from the decomposition of organics. In my humble view, nothing should be done to quicken the loss of this CO2.
Some may have heard of the "siesta" method to discourage algae. The principle is that the tank lights are on for say 5 hours, then off for 3-4 hours, then on again for 5 hours. Leaving aside issues this can cause for the fish, the reason it works to prevent algae is due to the CO2, not the light. CO2 is constantly being produced, but in bright light and assuming other nutrients are present at sufficient levels for the specific plants, the CO2 is usually the first nutrient to become exhausted. Algae then has an advantage. But the mid period of lights off allows the CO2 to rebuild, so when the lights then come on again the plants can merrily start photosynthesizing because CO2 is higher. It is possible however to find a good balance without resorting to this method. My tanks currently have 8 hours daily of tank light, and this is working for the level of nutrients I provide, the natural CO2, and the moderate light, and the plant species' needs; plants are thriving, and algae is present but not troublesome. To show how delicate the balance is, in the summer I used to see algae increase rapidly; then I worked out it was due to the increase in duration and brightness of the daylight entering the fish room, so I now keep the windows well covered, and over the last three summers, problem gone.
It takes longer and it uses more effort for aquatic plants to assimilate CO2 from the water than from the air. This is why floating plants grow so fast; they have what Walstad calls the aerial advantage, of being able to take up considerably more CO2 and faster than the submersed leaf plants. And the brighter the light, and the more available the 16 nutrients, the faster the CO2 is taken up. Plants will photosynthesize full out, until something is no longer available in sufficient quantity.
My canisters all return the water below the surface. There is some movement in the area of the spray bar, but not further out. I have had heavily-stocked tanks, fairly well planted, run like this for 20+ years and never noticed any evidence of oxygen shortages. The rate of fish respiration is a good guide.
Byron.
Some surface disturbance likely won't have much effect on the plants. However, we are talking natural or low-tech setups here. A high-tech planted tank with diffused CO2 is a different thing. My comments will be with respect to low-tech, meaning no artificial CO2 addition.
For years, all planted tank writers advocated no excessive surface disturbance (airstones, bubblers, surface movement) because it drove off CO2. A couple years ago, some writers changed, and began advocating the opposite. I was part of an extensive exchange of data on this issue on one of the specialist plant forums with people like Tom Barr. To date, there are no accurate scientific studies to prove this new viewpoint, so any benefit is not assured. There is plenty of evidence to prove that CO2 is driven off faster. This is important because the dissolved CO2 in the aquarium has to be higher per volume than in the air in order to provide sufficient carbon for the plants. CO2 is produced by respiration of fish, plants and bacteria as others mentioned; but the greatest source is in the substrate, from the decomposition of organics. In my humble view, nothing should be done to quicken the loss of this CO2.
Some may have heard of the "siesta" method to discourage algae. The principle is that the tank lights are on for say 5 hours, then off for 3-4 hours, then on again for 5 hours. Leaving aside issues this can cause for the fish, the reason it works to prevent algae is due to the CO2, not the light. CO2 is constantly being produced, but in bright light and assuming other nutrients are present at sufficient levels for the specific plants, the CO2 is usually the first nutrient to become exhausted. Algae then has an advantage. But the mid period of lights off allows the CO2 to rebuild, so when the lights then come on again the plants can merrily start photosynthesizing because CO2 is higher. It is possible however to find a good balance without resorting to this method. My tanks currently have 8 hours daily of tank light, and this is working for the level of nutrients I provide, the natural CO2, and the moderate light, and the plant species' needs; plants are thriving, and algae is present but not troublesome. To show how delicate the balance is, in the summer I used to see algae increase rapidly; then I worked out it was due to the increase in duration and brightness of the daylight entering the fish room, so I now keep the windows well covered, and over the last three summers, problem gone.
It takes longer and it uses more effort for aquatic plants to assimilate CO2 from the water than from the air. This is why floating plants grow so fast; they have what Walstad calls the aerial advantage, of being able to take up considerably more CO2 and faster than the submersed leaf plants. And the brighter the light, and the more available the 16 nutrients, the faster the CO2 is taken up. Plants will photosynthesize full out, until something is no longer available in sufficient quantity.
My canisters all return the water below the surface. There is some movement in the area of the spray bar, but not further out. I have had heavily-stocked tanks, fairly well planted, run like this for 20+ years and never noticed any evidence of oxygen shortages. The rate of fish respiration is a good guide.
Byron.
I just get a small ripple on my 75 and my oxygen content is fine, and I am very heavily stocked.
I do however run two airstones, only at night for a few hours though, because I run co2 during the day. I only really bother with the airstones because when I converted to planted, the stones were already there....and I figured it'd be easier to leave the stones where they are and make use of them with a timer than it would be to just pull them out (given that I had them behind and buried under the hardscape).
I do however run two airstones, only at night for a few hours though, because I run co2 during the day. I only really bother with the airstones because when I converted to planted, the stones were already there....and I figured it'd be easier to leave the stones where they are and make use of them with a timer than it would be to just pull them out (given that I had them behind and buried under the hardscape).
