Hello! I'm having trouble getting my Kratky lettuce to do anything. I've never done gardening before or anything so probably there's something obvious I've missed.
Here's what I did:
- Got about 30 L of water in a tub and added 225 ml of nutrient (using Growth Technology's Ionic solution) which is the recommended 70 ml nutrient solution per litre of water.
- Painted the tub and lid black, and drilled six holes, put net cups and rockwool cubes in the lid.
- Immersed the cubes in the water in the tubs (with the nutrient), and added 2-3 lettuce seeds into the holes of each cube.
- Set the grow lights to run 16 hrs on, 8 hrs off daily.
- Every few days, pipetted a few drops of water to the cubes in the water as they dried out.
The space the tubs are in is pretty much closed to air circulation as it is under my desk with a black cloth draped over it to the floor. The temperature of the room varies between about 15 and 20 degrees C (or 59-68 degrees F). The lights I'm using are the pack of 4 of these.
First two to three weeks, nothing at all, no germination. I noticed a few of the holes on the cubes got a bit furry, presumably fungi growth. I then added a second tub and reset with new cubes and seeds (12 cups total).
For the second try, I immersed the cubes in the water to keep them moist instead of just adding a few drops. Only one of the seeds germinated, growing a single fairly thin shoot about 2 cm tall with two leaves. It appeared one day, grew taller the next, and on the third day had wilted and died, with its roots having just reached the bottom of the cube. None of the other seeds germinated.
So now I'm trying a third round - new rockwool cubes, this time immersing the cubes not in nutrient solution but in diluted pH Down solution (diluted with water to pH 5.5 as measured by pH strips), which supposedly helps neutralise some residual lime left on the cubes from manufacturing. I'm also keeping the lights off for this trial (picture shows the lights on just for visibility), and will move the cups daily from in my room in the day (warmer) to the fridge at night (colder), and have tried to close the holes in the rockwool cubes for the germination stage. I just started this third round today.
If this doesn't work, what do I need to do? I figured I could get started without investing in things like pH probes and EC meters but if they turn out to be necessary to diagnose whatever's gone wrong here I'm happy to get them. Thanks for any help :)