yellow lettuce and poor spindly growth
by Mike Hart
I have an ebb and flow system, home built. Trays of clay pebbles with a syphon tube at one end. I pump nutrients into the tray once every three hours, where once up to the syphon level they drain and return the nutrient to the tank. Most of the time the trays sit with about 1-2 cm of nutirent in the bottom but there are times when the trays are part way between full and syphoned.
Whole system sits in a large green house. I am currently using a purcheased solution A & B makeup and am following the dilution on the instructions .and adding low levels of hydrogen peroxide on a weekly basis. I run the pH at 6.0 - 6.5 and the nutrient temperature is at 20c.
I understand that lettuce requires a high potassium level but am not adding further to the nutirents. I also have trays of peppers and spring onions all of which are failing to thrive.
The peppers I have in a tray fail to generate any root system and the onions hardly grow at all, and what there has been is more in the form of small onions instead of spring onions. The lettuces I have grown are very leggy with very little root and in the early stages the leaves are a pale yellow.
I have considered changing the syphon height to increase the nutrient level and also wondered if there is too much light and temperature with it being in a sunny area of the greenhouse
Answer from Stella/Simon:
I would like to try to help with some suggestions, but I need more information. Is this your 1st attempt at Hydro? Or did you have success before and now this crop is a failure?
Your numbers sound pretty good, my 1st question would be how hot does it get in there? The air temp?
Have you had success with these nutrients before? Sounds like the problem might be nutrition honestly. How often do you change the solution? Do you test it with a CF meter?
Hope this helps!
***Do you have any knowledge on this subject? Then please join in and leave your thoughts and suggestions below. Help and be helped in the Forums!