For skimmers and cultures
Air Guard
Your skimmer is the biggest gas exchanger on the tank, and every litre of air it drives into the water came out of the room it is standing in. Air Guard goes in front of it: activated carbon for VOCs, fumes and organics, then an H11 HEPA membrane for dust, mould and airborne bacteria.
The same block does the same job on a culture line.
- Filtration
- H11 HEPA + activated carbon
- Connections
- 4mm barbed, IN and OUT marked
- Power
- None, it runs on the pump you have
$46.00USD
Pre-order. Expected to ship mid October. Order now and yours goes out with the first run.
Fits any standard 4mm airline, on a skimmer intake or a culture manifold. Inlet and outlet are marked and it goes in without tools.
- Both media are replaceable, so the housing outlasts them.
Inside it
Everything in the air path, laid out
Four screws and the block opens. Both media lift out and drop back in, which is the whole reason the housing is built to outlast them.
Shown exploded so the order of the parts is visible. Drag it, or use the arrow keys.
The air path
Carbon first, then HEPA
Order matters. Carbon takes out what would otherwise clog a membrane, so the HEPA is left doing the one job it is good at and lasts longer for it.
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In
Whatever the room has in it
Air arrives off the pump or through the skimmer intake carrying everything that was in the room with it.
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Stage one
Activated carbon bed
A packed bed adsorbs VOCs, fumes and organics. It goes first so the membrane behind it is never asked to do this part.
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Stage two
H11 HEPA membrane
What is left meets the membrane, which catches airborne spores, mould and bacteria down to fine particulate.
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Out
Clean air, same 4mm line
Out through the marked outlet and on to the skimmer or the culture manifold, at the pressure your pump already makes.
All of it inside one sealed block, on the airline you already have. Four screws open it when either medium is spent.
Why bother
What your skimmer is actually drinking
A skimmer runs air through your water all day, which is exactly why it stabilises the tank. It also means the room is an input to the system, and nobody treats it as one. Whatever is in the air is going into the water.
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The room gets into the water
Cooking fumes, aerosols, paint, solvents, cleaning sprays and dust all reach the tank through the skimmer intake. This is the only thing standing in the way.
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Set and forget
No power, no noise, no routine. It sits inline and does its job every second the skimmer or the pump is running.
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Cheap against what it guards
A display tank, or weeks of culture work and the starters behind it, are worth a great deal more than the filter in front of them.
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Serviceable, not disposable
Swap the carbon and the HEPA when they are spent. The housing stays.
On a skimmer
Run the skimmer on outside air
With an outside line
Lower CO2
The air your skimmer wants
Filtered on the way in
The room your tank sits in runs far higher in CO2 than the air outside, because people breathe in it and the windows stay shut. A skimmer drives that room air through your water all day, which is why plenty of well kept tanks sit stuck at a low pH.
So take the intake outside. Run airline from outside to the marked IN, then a second length from OUT to your skimmer. Outside air is lower in CO2, but it is not cleaner: pollen, dust, smoke and whatever the season is doing all arrive with it. Filtering it on the way in is what makes the swap worth doing.
Keep the run as short as the window allows, and check your skimmer's air draw once it is fitted, the same as after any intake change.
Keeping it working
What to change, and when
Both media are consumable. As a starting point the carbon goes every three months and the H11 HEPA membrane every six, but how fast they load depends on the air they are asked to clean. Change the carbon sooner if the air leaving the filter carries any smell, and the membrane sooner if flow down the line drops off or the pump starts working harder.
Everything here, in one pack
AK Air Guard Recharge Pack
Two activated carbon beds and two H11 HEPA membranes. Both stages of the filter, twice over.
A filter on a pump in a dusty shed will not last as long as one in a clean room, and neither will match a pump sitting in a garage next to a running car. If you are only changing one, change the carbon: it is the one protecting the other.
Before you ask
The skimmer questions
The three we get asked most, answered straight.
Where does it go on a skimmer?
Inline on the skimmer's air intake, between the room and the skimmer. Inlet and outlet are marked, it takes standard 4mm airline, and it goes in without tools. On a culture setup it goes on the pump instead, so everything on the manifold is covered at once.
Better again, take the intake outside: airline from outside to the marked IN, and a second length from OUT to the skimmer, so what it draws is lower in CO2 and filtered before it reaches the water.
Will it raise my pH?
Not on its own, and we are not going to pretend otherwise. Activated carbon adsorbs VOCs, fumes and organics. It does not remove carbon dioxide, so this is not a CO2 scrubber and it will not lift pH the way soda lime does.
If pH is what you are chasing, the lever is where the air comes from rather than what filters it. Outside air runs far lower in CO2 than a closed room, so run your skimmer's intake outside and put the Air Guard on that line: what arrives is both lower in CO2 and free of the pollen, dust and smoke that came with it.
Will it restrict the air my skimmer draws?
Any inline filter adds some restriction, and this one is no exception. Fresh media is the freest it will ever be, which is a practical reason to change it on schedule rather than run it into the ground.
Worth checking your skimmer's air draw after you fit it and adjusting as you would after any intake change.
In the box
- 1 Air Guard filter, assembled
- 1 Activated carbon bed, fitted
- 1 H11 HEPA membrane, fitted
The numbers
- Housing
- 109 x 93 x 66 mm sealed block
- Filtration
- H11 HEPA membrane and activated carbon
- Carbon basket
- 48 x 46 x 19.9 mm, replaceable
- Connections
- 4mm barbed inlet and outlet, marked IN and OUT
- Fits
- Any standard 4mm aquarium airline
- Mounting
- Inline. Wall mount sold separately
Full product description
An inline air filter built for culturing rather than adapted from an aquarium part. Air from your pump passes through an activated carbon bed, which strips VOCs, fumes and organics, then through an H11 HEPA membrane, which catches spores, mould and bacteria.
It runs on no power and makes no noise. Fit it once at the pump and every vessel downstream on the manifold breathes the same filtered air. Both media are replaceable, so the housing outlasts them.