Leaftip burn on large outside dwc system

[Caribbeanguy]

Hello am a newbee my self and this my second month of growing lettuce mineto iceberg in the caribbean I am not growing in a green house or such first month was fine second month I notice tip burn and it has gotten worst I changed out all 1000 gallons of water and nut but the tip burn is still present using master blend 4-18-38 calcium 15.5.0.0 and epson salt at the recommended ratio of 2 to 2 to 1 respectively ec is between 5.7 and 6 normally resting at 5.8 what else can I do I even changed my formula by doing 200g calcium 150g master blend and 50 epson salt to see if my calcium level was too low remember my system is outside so wind is blowing directly on the plants all the time but at the same time sun is also on them

[imafan26]

If you are growing in a tropical climate we cannot grow grow lettuce well in summer. Tip burn happens when the days are longer and hotter. Lettuce starts to head up like cabbages, they are bitter and we get tip burn. Iceberg is hard to grow in the tropics, period. I had the best luck with the lettuce variety Ithaca, but I could only grow that in months that the temp was less than 75 degrees.

Heat tolerant lettuces can be grown under shade cloth if you live in a higher elevation with morning sun. Salad bowl, Grand Rapids, Lolla Rosa, Merlot, Jericho, Speckled bibb lettuce, Red Sails,and Anuenue.

I gave up trying to grow lettuce from June-October. Unless you pick you lettuce as baby greens they cannot take the heat. I just fed 5 manoa lettuce heads to the worms. They were already cabbages and bitter. I have a few lettuce seedlings and I am going to harvest them as baby greens.

[Caribbeanguy]

Thank you for the reply yes I am in the tropics lesser antilles just a fee hundred miles away from Barbados, I was fine from February to may which is our dry season we are now coming into the wet season/hurricane indo believe the days are getting longer as you said but not sure if its hotter now than in the dry season.. ill have to check so would it be possible for me to maybe put up shade cloth to cut back on some of the light....?

[Caribbeanguy]

These are the seeds am using btw