Growing Lettuce on Raised Beds
 

Dear All,

I am currently growing lettuce in a sand and paddy shell mixture in the Caribbean and is being irrigated using drip tape. I am confused on when to irrigate with the nutrient solution and when the irrigate with water only and how frequently. Any suggestions would be appreciated.

The hydroponic solution I am using is as follows:
For four (4) liters of water:
A. CONCENTRATED SOLUTION OF MAJOR NUTRIENTS
GRAMS
Mono-potassic Phosphate 190.0
Magnesium Sulfate 400.0
Potassium Nitrate 440.0
B. CONCENTRATED SOLUTION OF MINOR NUTRIENTS
GRAMS
Fertilon combo 20.0
Boric acid 4.6
C. CONCENTRATED SOLUTION OF N C
GRAMS
Calcium Nitrate 590
DOSAGE
Solution cc. per 1 liter of water
A 5.0
B 2.5
C 5.0

I'm not sure why you are giving them just water as they need the nutes to grow; I would just give them the nutes everytime. Some people want to flush their crops just before harvest with plain water but I have never done that and the vegies taste great!

It was recommend that I give them the nutrients in the morning and water in the afternoon for 6 days, and on the 7th day I flush it by giving them just water both in the morning and in the afternoon.

Personally I use an Injector system for my nutrients and I run nutes 5 days a week every time it runs then do plain water 2 days. I've run nutes 7 days a week vs the 5 days and haven't been able to tell any difference in the crops and it saves me on nutes. I grow in coconut coir.
In my recirculating system I run the nutes all the time as it's easier then changing tanks where as with the injector board it's just turning valves