NFT flow rate and Dept

[Chandara Khan]

Since I'm new with NFT , could you tell me what is the ideal flow rate and the dept of water in the troughs or pipes of NFT system? If possible tell me the links. Thanks!

[TCLynx]

NFT stands for nutrient film.  Basically a thin film of flow of water in across the bottom of the trough is all that is really needed.  How much water is needed will depend on the size of the troughs and the plants in the troughs.

 

My "NFT" pipes are not actually troughs but pipes and my plants don't sit down to the bottom of the pipe so I actually have deeper water flowing through my pipes but there is generally still an air space between the bottom of my "net pots" and the water and I use wicks to make sure I can start seeds or plant small seedlings without needing to top water the plants until their roots reach the water down below.

http://www.aquaponiclynx.com/my-net-pots-or-cups-with-wicks

 

Now it is important to know that NFT systems need the water to be filtered before sending it to the Trough, simply sending fish tank water to the NFT does not work well, the plant roots get gunked up with fish poo and things tend to get smelly so make sure there is filtration before the NFT pipes.

 

Also, Long NFT runs can deplete water of dissolved oxygen as well as tending to heat the water too much in hot weather or in cold weather the water in NFT pipes will get chilled.

[Chandara Khan]

Hi TCLynx! Thank you so much for your share. Actually, I understand the basic as well as the process of this system, but what I wanna know exactly is the suitable flow rate of water through the troughs. Oh, I'm also using PVC pipes for my system as well since throughs are not available here (Cambodia). Could you tell me about the filter that you are using right now? Here the weather is okay (Tropical weather) . My system is not afraid of cold weather. Thanks!

[TCLynx]

My water goes through gravel beds to filter it before I pump it to the NFT pipes and Raft bed and towers as well as pumping back to the fish tank.  I have what I call a "clean water sump" since all my fish tank water goes through gravel beds before draining back to the sump.

 

I really don't know the exact flow rate I'm sending through my two 15 foot long NFT pipes, It is through a 1/2" pipe and I have a ball valve on it that is normally closed about half way.  I've never timed how long it would take to fill a bucket.