There wouldn’t be much flushin going on if the grower would heed to two simple things
1.) Soil
And
2. Feeding nutrients
Never fed seedlings.! Durning the hole grow they need very little nutrients and I mean very little because this s where everyone makes there mistake over feeding and or using nutrient laced soii = Deficiencys.
Over or under watering willing cause major probems. But if you makeup yoursef schedule and keep to it you’ll be fine