Air Pumps, Is watts/gallon 1W/G really an accurate measure

scottledeuce

Active Member
Hi all,

I've been searching here for some air pump answers and while learning a lot ended up with a lot of questions too.
First that comes to mind is I've heard a lot of people talk about it's pumping ability in terms of Watts/Gallon.

People here are usually quite exact so I would have expected the measurement to be the actual output and not the power capacity?
Is watts per gallon an accurate measure?

Where I live we use metric so I usually talk liters/min but if this is true does it mean my pump is not up to scratch.
Here is mine: https://www.grow-in-berlin.net/beluftungspumpe-240-l-h-forderhohe-1-2-m-4-w.html

It does 400L/Hr which is 6.66 L/Min and sits in a 45 L container.
That's about 1.75Gallons/Minute to a 12 gallon tub.
The pump itself consumes 4 watts so in theory should only be good for 4 gallons right?

However whats confusing the hell out of me is I chose it over the following as the one below pumps 600 L/Min but draws 15 Watts and is over twice the price for a 50% gain in pumping ability: https://www.grow-in-berlin.net/beluftungspumpe-600-l-h-forderhohe-1-m-15-w.html.

Anyway right now I have my seedlings in 6 netpots in the same container but soon I will move them to 6 separate 20 liter buckets and need a pump/ pumps that will keep them all happy.

Is anyone able to clear up what sort of output I should aim for per liter of water, I know most people here are American and use imperial so gallons is fine if that's what you think in, It's just hard to figure out right now when hear so much conflicting measures.

Here is a pic of my current pump in action. DSC02505.jpg


Also Is there different (how do I say) types of mechanisms inside different pumps, The one I have now is nice and quiet and while I would love a powerful one that would take care of them all I have this feeling that as they scale up they start to sound like those portable air compressors you get to pump up a flat tire in an emergency :-P

I have a feeling outdoor pumps for ponds and the like don't have to be as silent by nature and I'm already running a 360M3/Hr extraction fan there which is not exactly silent but I don't want it sounding like a tractor either so are larger pumps proportionally louder by nature.

If anyone here is from Europe and can recommend one it would be great also

Thanks
 

redi jedi

Well-Known Member
The watt/gallon is more a suggestion than rule. Alot of air pumps dont list there volumetric output so the wattage is used to gauge the output. I wouldnt worry about the wattage too much. Its quite possible to get a pump that uses less power but produces more output.

Myself, I aim for 10L/min. So if I was running 6, 20L buckets I would use a 60L/min air pump or better.

Outdoor pond pumps, IMO, are the best. They are very quite and durable and produce much more output than a typical piston or diaphragm pump you see listed for hydroponic use.
 
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