An airstone, is a small porous device that diffuses air into an aquarium. This creates a constant stream of tiny bubbles that serve several beneficial purposes. But do you need one?
Airstones help oxygenate the water, which is vital for fish respiration. They also improve water circulation and break up protein film on the surface. However, there are some cases where an airstone may not be necessary.
This comprehensive guide will examine how airstones work, their pros and cons, whether your aquarium needs one, types of airstones, setup and placement, and how to use airstones effectively. Read on to better understand aquarium aeration and decide if an airstone is right for your tank.
What is an Airstone and How Does it Work?
As the name suggests, an airstone is a stone-like porous material that helps aerate aquarium water. It’s connected to an air pump by plastic tubing, diffusing the pumped air into the water as tiny bubbles.
The bubbles serve several key functions:
- Oxygenation – As the bubbles rise and pop at the surface, they facilitate gas exchange, introducing more oxygen into the water. This oxygenates the water, giving fish and other creatures the needed oxygen.
- Circulation – The steady stream of rising bubbles creates water movement and circulation. This brings oxygen-rich water from the surface downwards and around the tank.
- Surface agitation – The bubbles breaking at the surface agitate the water, preventing surface protein film from building up. This film can prevent proper gas exchange.
- Remove waste gases – such as carbon dioxide, that can build up from respiration and decaying matter. The bubbles help gas off these waste gases.
So in summary, the constant shower of tiny bubbles from an airstone oxygenates, circulates, and de-gasses the aquarium water to create a healthy environment for tank inhabitants.
Do You Need an Airstone for Your Aquarium?
While airstones provide useful benefits, they are not mandatory for all aquariums. Here are some factors to consider when deciding if your tank needs additional aeration:
Oxygenation From Other Equipment
Many filters and powerheads create surface agitation and water movement that somewhat oxygenate the water. You may already have adequate gas exchange if you have strong water circulation.
However, heavily stocked tanks often benefit from extra oxygenation from an airstone. The more fish and creatures you have, the more oxygen they require.
Larger aquariums tend to necessitate extra aeration. With a bigger water volume, gases like oxygen diffuse more slowly from the surface to lower depths. An airstone helps circulate and diffuse that oxygen throughout the tank.
Small desktop nano tanks often don’t need airstones though, as their compact shape makes gas exchange easy.
Fish Species and Livestock
Some fish naturally require more highly oxygenated water than others. This includes:
- Labyrinth fish like bettas and gouramis can breathe oxygen directly from the surface.
- Active fish like danios that need more oxygen.
- Invertebrates like shrimp and crabs that are sensitive to oxygen levels.
For tanks with these creatures, an airstone gives them the oxygen levels they thrive in.
Densely planted aquariums can Create low oxygen zones, especially at night when plants switch to respiration and consume oxygen. Here, airstones help prevent these oxygen dips.
Sparsely planted tanks are less likely to need extra aeration. Just be sure plants don’t completely cover the water surface and prevent gas exchange.
Warmer water holds less dissolved oxygen than colder water. Therefore, aquariums with heaters may benefit more from airstones to introduce sufficient oxygen.
Symptoms of Insufficient Oxygen
Watch for signs of low oxygen, like fish gasping near the surface, sluggish behavior, losing appetite, and hiding at the bottom. If you spot these, an airstone can likely help.
So, in summary, the more crowded, large, warm, and planted your aquarium, the more active your fish, the more you’ll likely benefit from an airstone. They also serve as handy backup aeration for any tank.
Benefits of Using an Airstone
When utilized properly, airstones offer several advantages beyond just basic oxygenation:
- Helps fish breathe easier and reduces stress
- Promotes active, healthy fish
- Encourages strong plant growth and photosynthesis
- Discourages anaerobic bacteria that thrive without oxygen
- Oxidizes harmful gases like hydrogen sulfide
- Breaks up surface biofilms that inhibit gas exchange
- Improves circulation and evenly distributes heat
- Can increase oxygen for live aquarium foods like brine shrimp
- Low cost and simple setup
The stream of bubbles is also visually appealing and adds movement to the tank. Just be sure to find the right balance – excessive bubbles can agitate some species.
Potential Downsides of Airstones
While airstones have many benefits, there are a few potential drawbacks to consider:
- Can be noisy, especially coarse-pored stones and high pump settings
- Lots of bubbles disrupt the water surface and outgassing of CO2 needed by plants
- High flow pumps that push too many bubbles can cause stress
- Excess bubbles can strip out essential dissolved organic compounds
- Equipment like pumps require cleaning and occasional replacement
These issues are usually remedied by using finer bubbled stones, adjusting air flow, and finding optimal placement. Overall, the benefits of aeration usually far outweigh any downsides.
There are a few main airstone options and materials to choose from:
Ceramic stones are perhaps the most common type. They’re made from fired clay or porcelain and come in various shapes like discs, domes, cubes, and rods. Ceramic evenly diffuses air into fine bubbles.
Fused glass or silica crystals are another option that produces a pleasing stream of tiny bubbles. The glass can be colored for decorative effect.
Porous wood can also diffuse air when soaked. However, wood tends to be less durable and produce larger bubbles.
Molded plastic air stones are inexpensive but don’t produce as fine of bubbles as ceramic or glass.
Shaped like tubes or wands, these produce a wall of bubbles rather than individual bubbles. The bubble wall helps increase surface gas exchange.
These connect to air tubing and sit on the bottom, producing bubbles from small holes in the disk. This sends bubbles upwards, generating circulation.
You’ll also need an air pump to power the airstone. Air pumps use electricity to compress air and deliver it through the tubing to the stone. There are a few pump types:
- Standard – Reliable and reasonably quiet. Good for average use.
- High-volume – For large tanks, multiple stones, or more bubbles. Can be noisy.
- Adjustable flow – Lets you control airflow as needed. Useful for finesse.
- Linear piston – Alternates air output between two outlets for even pressure.
Aim for a pump with enough power for your needs, but don’t oversize. If possible, get a pump with adjustable flow and use a check valve to prevent backflow.
Airstone Setup and Placement
Setting up an airstone is straightforward:
- Select an appropriate air pump for your tank size.
- Choose one or more airstones that produce bubbles fine enough for your needs.
- Attach airline tubing between pump and airstone. Secure with check valve.
- Position the airstone ideally near the filter outflow or powerhead to disperse bubbles.
- Adjust flow to achieve gentle circulation without excessive bubbling.
Some key tips for placement:
- Place near tank filter or powerhead for circulation and distribution.
- Position away from heaters to maximize oxygenation.
- Avoid planting dense plants immediately around the airstone.
- Keep away from intake tubes that could suck in bubbles.
- Angle the stone upwards slightly to drive bubbles toward the surface.
Experiment with positioning to find the sweet spot in your tank. Also check that hardscape, decorations, and plants aren’t blocking surface gas exchange.
Operating Airstones Effectively
To maximize the benefits from your airstone while avoiding potential downsides:
- Use an appropriately sized air pump and stone for your tank. Oversized pumps tend to be noisy and push too many bubbles.
- Adjust air flow to create surface rippling but not churning. Excessive bubbles are counterproductive.
- Perform occasional cleaning on the pump, tubing, and airstone to maintain steady airflow
Troubleshooting Common Airstone Problems
Even when set up correctly, you may encounter issues with airstones. Here are some common problems and solutions:
Not enough bubbles
- Clean airstone to remove gunk clogging pores
- Ensure tubing is connected and intact
- Check pump is running properly and fully submerged
- Try a more powerful pump if needed
Bubbles too large
- Switch to a finer grain airstone material like ceramic, glass or finer wood
- Reduce air pump flow rate
Bubbles only from part of airstone
- Soak stone in bleach then rinse to open all pores, or replace
- Ensure stone is level in the tank
- Turn down air pump flow rate
- Move pump onto foam pad or rubber feet to dampen vibrations
- Switch to quieter pump like linear piston or diaphragm types
Fish seem stressed
- Redirect or reposition airstone to lower bubble turbulence
- Use an air control valve to turn bubbles down
- Diffuse bubbles by placing near filter outlet
Green gunky buildup
- Remove airstone and soak in bleach, rinse well and replace
- Keep tank and equipment cleaner to limit algae growth
Bubbles sucked into filter
- Reposition airstone away from filter intakes
- Redirect filter outputs to distribute bubbles better
With some adjustments and cleaning, most airstone issues can be corrected easily.
FAQ About Airstones
How many airstones should I use?
One properly sized airstone is usually sufficient for most average tanks under 55 gallons. For larger aquariums, use two stones on opposite ends. More than two is rarely needed.
Where can I place airstones?
Ideal spots are near filter outflows, powerheads, or the back glass pane facing forward. Avoid directly under heaters.
Do I need an airstone for a betta fish?
Bettas and other labyrinth fish can breathe surface air, so airstones are not essential. However, they help oxygenate resting areas when the fish aren’t at the surface.
Can I leave an airstone on 24/7?
Absolutely. Airstones are designed to run continuously. Turning them off for periods can cause fluctuating oxygen levels.
How often should I clean the airstone?
Clean airstones every 2-4 weeks by removing and soaking in dilute bleach. Rinse thoroughly before replacing. Keep an extra stone on hand.
Why are my fish gasping with an airstone?
Ensure bubbles are reaching lower levels. Redirect the airstone, increase pump flow, or add a second stone to improve circulation.
While not mandatory, airstones are highly useful accessories in most home aquariums. The stream of fine bubbles oxygenates, circulates, and de-gasses the water to establish a healthy habitat for fish and aquatic creatures.
Carefully select the right air pump and porous stone for your needs. Position the airstone strategically, and adjust the airflow to achieve gentle rippling at the surface. Perform regular cleaning and maintenance for optimal performance.
Monitor your aquarium inhabitants and plants for signs of insufficient oxygen. Add an airstone or two if you notice issues, especially in larger, crowded, or densely planted tanks. The inexpensive investment helps provide peace of mind that your aquatic pets can breathe easy!