This is my 5th or 6th lettuce grow using hydroponic methods. I haven’t done an nutrient film technique (NFT) as of yet, but I just built simple system that you can read about in my post a quick and sloppy NFT system from PVC.
October 3, 2019
I started with the standard procedure of soaking eight rockwool cubes in distilled water at 5.5 pH using pH Down. I sowed about 3-4 crisp mint lettuce seeds per cube for maximum results. I really wanted the green leaf lettuce variety, but I didn’t have any on hand.
Note: I opted to not put any nutrients in the rockwool soak solution, no reason why other than laziness perhaps? I do mix up a very light solution of distilled water and master blend, calcium-nitrate and epsom salt to feed the seedlings along the way.
Once my cubes were seeded I dropped them in the propagation chamber, set my T5 florescent on a automated TP-Link plug for 12 hour cycles. I also have a heating pad, but I have not had to use it. It’s been a task to keep my cubes sub 80 degrees here on the tail end of summer in the house.
I have so much PVC laying around so I fashioned up a rack for my light out of spare parts. Also, in the photo you’ll see I have removed the dome and raised the plants up very close to the light. Once my seeds get some leaves I typically remove the dome. Also I noticed the lettuce were looking leggy so I raised it up. The T5 lamp I have isn’t doing a very good job as it’s only 2 bulb.
Note: This is a temporary setup until I finish out my grow tent in the garage and sort out the temperature situation.
October 13, 2019
Most of the seedlings have come out of the rockwool. All have sprouted, but I placed some a little lower in the cube than I’d like, so they are taking a bit longer to get to the top. Everything looks pretty good aside from possible leggy-ness caused from the lamp being too far away.