no that will be perfect for germinated seeds and rooted cuts in a smallish pot say 4"square, a combination of having such low soil npk ratio and using the wet-dry watering schedule will make yr plants root out the pot much faster as the roots grow out in search of water and nutes, when u got plenty of roots showing at the holes in the pot then transplant into yr final pot size with a good organically pre-fertilised soil, i use canna terra proffesional soil with an npk ratio of 12-14-24, conductivity(the concentration of that npk in the soil) of 1.1-1.3ms and ph buffered @ 6-6.5. All this info should b on the bag. I like to use a final pot size of 10l or 2.5gal, big enough for a decent root ball but not so big that i cant get a decent amount of plants in my floorspace, doing it this way u will not need to feed throuhout veg at all just straight water, eau de tap! If u flush now u will only further wash out what little ferts there is in the soil, why on earth would anybody flush if they havnt even fed anything yet?? And y would u flush if over-watering is suspected only to add to the problem?? Too many people too quick say flush. Just pot up in a larger pot with a soil like i described above and use the wet-dry cycle and yr yellowing will stop and ul b fine until onset of flowering and probably beyond, and i wouldnt recommend letting yr plants wilt off regularly between waterings, yes yr plants can survive this easy but in times of drought when the plants wilt the stomata, the tiny pores in the leaves close up to stop transpiration of water and waste gases in an effort to prevent moisture loss, photosynthesis comes to a halt, and toxins build up in the plant causing stress, not good, especially during bloom. Also when the soil gets too dry irrepairable damage is done to the fine roots and root hairs, just stick yr finger in the soil if u can feel any moisture 2inches down it dont need water, if it feels dry 2inches down give it another day then water, but ffs always before it wilts!