Backyard Aquaponics
A place to discuss aquaponics

I may have access to a 450w large aquarium air pump, is there a way to slow it down and save power? It is one of the piston types I believe.

Any details on the motor?
(series, squirrel-cage, etc)

If you cut it in half you will reduce its power consumption by 100% with a resulting 100% reduction in its air pumping capacity.

Run an extension cord from next door, 100% saving

You can get electronic speed controllers although they do not usually work with capacitor start motors eg http://www.jaycar.com.au/productView.as ... &SUBCATID= and I'm not sure how much power the controller wastes.

would check the power draw under various loads to see if it really pulls 450w.
Cheapest option would just be a timer .

+1
If it's the standard piston driven air pump, driven directly by the coil, then the piston will pump 50 times per second. if you change the frequency (from mains standard 50Hz) then it will pump faster or slower. There should be kits that will do this for you at places like Jaycar.
I think however a frequency modulator for 240V will be rather hard to come by.
remember this is an AC motor in principal so most motor controllers wont work. Places like Jaycar , Tricky Dicky, Altronics and Oatley et al are rather scared of selling kits that work with 240V.
Good Luck.

Oh. An electromagnetic one.
If you have access to a variac, see if it pumps air at another common voltage (e.g. 130VAC).
If so, your power should be down ~75% but you would have the expense of getting a conversion transformer.

Its one of these :

http://www.aquariumaccessories.com.au/product_detail.php?productsid=7&PHPSESSID=9254a8947e1062524cc82f3bb13d6c16



They still want $220 for a second hand one, so might give it a miss.

OBO

Check out this link http://www.aquariumproducts.com.au/elec ... _pumps.php
More air less watts cheaper price.
Also check their air blowers

Dont think the blowers [big volume no pressure no more than 12 in deep] look at there hi volume pumps also

I have a similar pump and use it to aerate 1000m2 of ponds. May be just a bit bigger than you need for your backyard system I recon.

You sure about that F&F? The HG 180 runs at 9kpa. Think pressure required to push to 1m is 9.8kpa.

Yep emailed dufflite [he got one in toys ] said blows lots of air but wont do depth
where high volume pumps For the same price do mpa not kpa the larger ones $600 do 13 kpa

Yes a small blower does not like to go past a meter ish. But it does do a lot of volume. And if you want to put the air stones in a PVC to the bottom it will move water. Volume and cost of running are the best things about it. If I was going to do it again. I'd still buy the blower.

I want to be able to push down at least 1m, so the higher pressure will be needed. I might get a couple of the smaller ones - much easier to run off an inverter.