Hello everyone

I am in my second year growing hydro herbs, tomatoes, lettuces etc and
coming along fairly well for someone who doesn't have too much of a green
thumb.

My problem is that I am not doing too well at raising seedlings. I have been
using coconut fibre (as used in hydro systems), perlite/vermiculite and
watering with seedling strength solution of Seaweed Fertiliser. I have tried
locating the trays of seedlings inside my shed which gets a fair bit of
indirect sunlight, I have tried under 70% (black) shade cloth, I have tried
in a tray with clear plastic cover. Each time I end up with very spindly
lettuce/rocket seedlings.

Does anyone know what I may be doing wrong?

Thanks

John