I really don't know about turtle waste, but near the bottom of this post there's some NPK values of other manures... http://community.theaquaponicsource.com/group/fish-less-systems/for...
Honestly...if it were me, I'd have a hydroton filled bed, and I'd bury the bottom few inches of all those smart pots below the water line of that hydroton filled bed. The AP water would flood and drain the bed (or constant flood, constant flow). I would measure the water holding capacity of a smart pot (how much water your soil mix will hold before water started to drip out the bottom) and cut that number in half or even two thirds and use that amount to "top feed" those heavy feeders. (Example: if each smart pot could hold 1 litre of water...I'd water them with 333ml of nutrient enriched water each).
The lower water seeking roots would hang out in (mostly nitrate rich AP) water, while the upper nutrient seeking roots would be top fed with 333ml of custom mixed nutrient solution (depending on that cultivars need in whatever particular stage of growth my plants happened to be in).
This is basically a slight variation on the dual root zone method I described in Jon's link. That is how I would do it. No soil filtering required, no extra beds equipment, no extra maintenance, smaller footprint, no fouling of AP water with excess nutrients, no problems (or need) to reclaim the hydroton from the soil mix after harvest, and a bio-filter and AP water devoid of any organic particles soil or otherwise...and plants that get the 'best of both worlds'. and if you wanted to grow some 'light feeders' directly in the hydroton...in between the smart pots, you could...I'd also throw some worms into the hydroton to help out with the fish/turtle solids...No need to flush the 'heavier solids' and throw away all those wonderful plant essential elements that are locked up within those solids.
About a month or more before you think you'll be ready to cycle the system, start collecting your urine in plastic bottles. Set them aside and leave them be. The urea will hydrolyze into ammonia (then called 'humonia'). NPK value is 11-1-2 plus many secondary and trace elements (Mg, Fe, Zn etc)...Use that instead of store bought janitorial ammonia, which will ONLY provide you with N...No P or K, nor secondary, nor trace elements...The process of cycling is the same no matter what you use. Just that your system is at a 'way' nutrient advantage right off the bat if you cycle with humonia.