Turning yellow

Hi @Jw3287 Although it looks like soil, coconut must be treated as Hydro and nutrients for coconut must be chosen. However, there are those who mix hummus and guano powder. If watering is manual, you should choose larger pots so that you don't have to water every day. The larger the pots, the lower the frequency of watering. The runoff must be discarded. Automatic watering: Usually a pump is placed in the Sn tank which in turn will distribute Sn through the plants. In this case it is not necessary to have very large pots and you can do several watering in the first hours of light, since watering in small amounts helps to oxygenate the roots. In automatic irrigation you can take advantage of the runoff, making it go back into the deposit, however most of the growers I know do not take advantage of the runoff, which has some positive aspects: A smaller fluctuation of Ph and Ec in the deposit of Sn. A “clean” solution. Less likelihood of gutter clogging.

When you are growing in coco there are no nutrients in it to support your plants like there are in soil. You need to start feeding a low dose (1/4 strength) around day 3 of the plants life. This is the problem with your plant. I hate to say this, but being at week 3 with an auto you have stunted her and it probably won't put off more than a couple grams if you can get it turned around. I would definitely do some research on coco and germinate some fresh seeds. Feel free to message me and I will be glad to share some more detailed info to help you get a new grow going and off to a better start. Good luck!

cotyledons turning yellow means it is eating itself. coco doesn't contain any nutes in it and right after 2nd week,you'll see it'll start using all its energy from cotyledons which means it is lacking nutrients at root zone to turn into growth energy.you should feed it in coco from day 1,at small doses.

Mate, I´m gonna start to grow in coco too. I strongly recommend you to visit the website cocoforcannabis.com since they have good tutorials regarding some aspects of the growing media (like buffer the coco for seedling stage), fertigation, preparing the nutrient solution, feeding schedules, etc.