Backyard Aquaponics
A place to discuss aquaponics

we're going to get my brother to think hard about a wind powered aerator. Using an old domestic fan (?) with the appropriate gearing etc connected to a small paddle wheel

That is an awesome idea, except when there is no wind. Unless you use windpower to charge batteries which in turn drive a paddle wheel aerator. Heres a website to get plans for a windgen it looks like you have the room for one: http://www.scoraigwind.com/index.htm This one http://www.scoraigwind.com/axialplans/index.htm can produce 12, 24 or 48 V at 500W.

thanks Tim

I have a cheapo chinese 12v aircompressor mounted in my landcruiser. It takes about 4 years to pump a tyre but refuses to die so I can justify buying a fancy german one :-)

This got me thinking, what about a cheap solar trickle charger feeding one or two car batteries (deep cycle if you are spendy enough). These cconnected to the compressor via a mains voltage failover swithing the 12v with the compressor outlet running through an airstone.

When the sun runs, the batteries charge. When the mains current fails the compressor starts and feeds the airstone till mains power is restored.

I've used the compressor to assist in burning out tree stumps by making an improvised furnace with a ploughshare as the roof and it runs off the battery in the cruiser for 10 hours easily. Even here we don't often see a 10 hour outage so it might be worth looking at.