Hi Murray,
So the floating Raft System is a continuous flow system?
and does this mean that the level in the fish tank stays the same? and does adding more grow troughs mean that by the time the water reaches the end one, the nutrients have been somewhat depleted. This system sounds good if like me you only want one pump and gravity feed back to fish tank! I have my milk vat in position in the milk room and I am finnishing off the lazerlighting on the milking shed, so I should be getting started soon!! Also Great workshop in Melbourne, Jack took all the info to school for show and tell, his teachers were very impressed!
Thank's Tamara Hookway.

You are welcome Tamara
In larger commercial floating raft systems the length of the grow bed can be up to 60 M. So distance is not a problem provided there is enough nutrient in the first place. Aquaponics is all about balance.
Keep me posted on your system build.
That Jack is some kid !!!

Hi Murray,
I am new to aquapoics and have yet to set up a system. I have been a pondkeeper for about 12 years. My pond is 11,000 gal. and and not heavily stocked so my nitrates are close to nil. I would like to set up a system using a 300 gal. tank and am curious as to whether you think a continous flow raft system or a flood and drain media bed system is best.

A raft system is good for growing lettuce and the like, but for a general home system the simplicity of a flood and drain gravel bed based system is hard to beat.