If you want to use Nutrient Film Technique (NFT) in your aquaponic system, you need to understand a couple key points. Also, there is a caveat...
NFT is a popular method
We have used NFT in several applications and found it works quite well with greens and strawberries. The grow space is limited to pvc pipe area and growing medium is restricted to net pots. We grew lots of lettuces, herbs and strawberries just fine.
Caveat using NFT
There are many ways to implement aquaponics and NFT is one. However, there are some caveats using pvc pipe in aquaponics and hydroponics. One is the grow space is very limited. Another is the root mass can restrict water flow causing backup of the system. Also, there are few plants that do really well. We have tried both pvc pipe and gutter or tray type channels. All work fine as long as you keep the roots trimmed.