Pedro_De_Pacas
Member
thescissors..that soker hose..Does that work pretty good for water aireation?...I was looking at that today ....but i wasnt sure if that would make a good bubbler system or not...What are your thought on this.?...PEACE
Pedro_De_Pacas said:thescissors..that soker hose..Does that work pretty good for water aireation?...I was looking at that today ....but i wasnt sure if that would make a good bubbler system or not...What are your thought on this.?...PEACE
clowntown said:Try using no stone, just an open line. There's been a lot of discussion as to whether small bubbles are actually beneficial in aerating a solution, or more surface agitation, and even with all the reading I was still a bit skeptical. That is, until the preliminary results posted by morgancola with his DO meter. Granted it wasn't very thorough or completely conclusive, but it did certainly show that it was plausible that running an open air line with no stone produced better aeration / higher DO than with an airstone. No more clogging to worry about, and quite possibly higher DO levels.
That's what I thought, initially:mrwags said:Take a look at at the air bubbles produced by an aquarium aerator. Watch how quickly the bubbles rise to the surface. They provide little aeration, but are aesthetically pleasing to watch. Bubbles must remain contacting the water, if they are to do the job properly. A good rule of thumb is: The smaller the bubble, the longer it will remain suspended in water to dissolve.
clowntown said:How was it determined that surface agitation is what provides oxygenation and not the bubbles rising through the surface? I've heard the whole powerhead theory and how it requires no airstones, etc. Isn't surface agitation providing oxygenation by exposing the water to oxygen via surface area? So why couldn't small bubbles do this on its way up, since there is a lot of surface area to be had?
inflorescence said:Because the bubbles are encased in a shell of surface tension of their own.
As the bubbles travel up no o2 escapes from the bubble into the water due to this shell. When the bubble reaches the top, the surface tension on the top is broken and gas can then permeate the water because of the temporary break in surface tension.
I've seen pics of insects that exploit surface tension by forming a gas bubble around their head and going under water to hide while they carry their extra 02 supply with them. Natures original SCUBA tank. Their o2 supply doesn't permeate the surrounding water because the surface tension encapsulates it.
Capillary action/surface tension is also one reason why large redwood trees over 300 feet tall can transport water up from ground level (their roots) to the top canopy 300 feet up. The trees don't actually "pump" the water up the internal plumbing of the tree but rather have adapted to have plumbing that is small enough in diameter to allow the water to "stick" to itself as it rises up the tree.
I even think I heard once why trees like redwoods can't grow taller than a certain height is because the force of gravity overwhelms the capillary action at some height and starts pulling the water back down. That's why there are no 2000 foot redwoods.
Why an Air Stone
While an air pump tube alone can bubble air into a nutrient solution, oxygenation or the process of getting atmospheric oxygen dissolved into the liquid nutrient, is much more effective where many tiny bubbles of air are created, rather than a slow stream of larger bubbles. The greater the surface contact between the air bubbles and the nutrient, the more oxygen will diffuse into the nutrient solution and smaller bubbles create a far greater surface area than a few larger bubbles will. Air stones simply break up the air flow and distribute along the surface of the porous 'stone' so that many tiny bubbles are rapidly introduced into the nutrient. Depending on the size or dimensions of the nutrient reservoir into which air is being introduced for oxygenation, air stones of different shapes and sizes can be selected. For small rectangular tanks, long thin air stones (some up to 1 foot in length) can be placed on the base of the reservoir to distribute air bubbles and oxygen uniformly. A larger number of smaller, round, cylindrical or oval air stones placed at equal distance inside a nutrient pool or tank also ensure high levels of oxygenation.
Air stones also have the benefit of acting as 'weights' which remain stable on the base, or in the lower layers of the nutrient tank - the further the bubbles have to travel to reach the surface of the nutrient, the more time oxygen has to diffuse into the liquid and the higher the rates of dissolved oxygen than can be obtained from an air pump and stone set up.
More testing is being done, but preliminary (simple) testing has shown that in buckets of plain water, an open-ended airline produces higher DO than one with an airstone:mrwags said:So I wonder if someone with a o2 water meter would do the group a favor and run a quick test?