nutrient questions???need help??pics

my question is when should i start using nutrients..
i have 3 seeds that just sprouted..
and one hat is 29 days old..

https://www.rollitup.org/members/eduardors77-albums-ne-08-grow-picture3704-29-days-old.jpg

https://www.rollitup.org/members/eduardors77-albums-ne-08-grow-picture3703-5-days-old.jpg

https://www.rollitup.org/members/eduardors77-albums-ne-08-grow-picture3702-5-days-old.jpg

https://www.rollitup.org/members/eduardors77-albums-ne-08-grow-picture3701-29-dys-old.jpg

https://www.rollitup.org/members/eduardors77-albums-ne-08-grow-picture3700-29-days-old.jpg

suggestions

the first fourth and fifth are 29 days old..
any suggestions on cheap nutrients to use to help it grow for more yield..

Supernaturl Aqua Grow for veg, and Aqua Bloom for flower.