Backyard Aquaponics
A place to discuss aquaponics

My lettuce plants (black seeded simpson lettuce) are growing very long. i did found out i have way to little fish for the amount of square meters i have so im gonna put some more fish, but i dont know if this is the problem.

the raft get about 7 hours of direct sunlight. above the plants i have the green shadow screen.

i googled the problem, but couldnt find a lot about this problem

From the looks of it your lettuce is bolting (going to seed) because your temperatures are higher than it likes. Looks like your day and night temps are both 80 F or above. Lettuce becomes bitter once it goes to seed. It's time to pull the lettuce and grow a warm weather crop. You might be able to find a lettuce variety that does better in warm climates but I'm not certain what the cutoff is for success especially with the high night temperatures. Looks like you're on the right track as far as selection but you might find something you can use in one of these -
http://www.tropicalpermaculture.com/growing-lettuce.html
http://echocommunity.site-ym.com/resource/resmgr/a_to_z/azch2pt2.htm
http://permaculturenews.org/2014/07/25/ ... ut-panama/

As Scotty,plus what are your air,water temps and humidity readings ?