watering

You can fertilize each time, but that depends on concentration of what you feed and method of growing. Even in soil you can put fertilizer in every irrigation if it's the right type of nutes and at a proper concentration for the frequency. You'll give rughly the same amount per week regardless, though growth will be faser with more frequent fertilizations (assumes safe concentration relative to frequency). In a soilless you definitely should be putting ferts into every single irrigation and a well-balanced 1.3-1.5ec range likely best. Some organice methods may not fit into that mold as well because you rely on microbes to break down what you put into soil to make it plant-ready. Much more difficult to balance out, but definitely doable. Don't let it sit in runoff. if there was any rising concentration levels due to evaporation or other lurking problems, guess where it'll be? Runoff is waste water. Use it outside, but don't give it to indoor plants. Sure you may not see any problems for a few grows doing this, but eventually, if you maintain that habit, it will be a cause of something you could have avoided with better practices. So in the end, not engouh info for this question. if in soilless, definitely. If soil, just depends on how strongly you feed. second, never think of it from the perspective of "i need to give X liters at this point in time" ... that's not how it works and you'll never be consistent. Too many variables to create a one-sized fits all volume to give based on age of plant. You irrigate until some runoff -- 10-20% for soilless since we provide a tightly controlled concentration for the medium in this method and the runoff should eliminate possiblity of sky-rocketing EC levels if consistent about it, but you only want mnimal runoff to be sure full pot is 'wet' with soil... otherwise you are just running your soil-nutes down the drain. Now, as long as you irrigate at same pot-weight at later point, it'll be a similar volume of water needed each time relative to 2nd irrigation, technically, since first irrigation may have been a different starting weight. So, when top 1" is dry, feel weight of pot. This is now your queue to water. You will be able to plan and predict how much water you need, but it may not be an integer value like "1L per pot". Rate of evaporation will be relative to temp/rh levels but also the plant will drink an increasingly faster rates. So the time between will vary, but the volume of water needed will remain roughly the same. You only learn that volume needed in hindsight your first time or from previous experiences. if you keep same soil product or same % of perlite mixed in, should be consistent in future too.

Never give nutes every time you water... you want to water/feed/water/feed.... and your plant should tell you how much it needs.... Lift your pot up, if it seems terribly lightweight, it needs something - if it still feels a little heavy, it doesn't need anything. Then, when you water, give it enough so that about 10-20% runs out the bottom.... let the pot sit in that runoff for about 15 minutes to see if the soil will soak any more water back up into it... keep watering it until the soil doesn't soak any more back up... and then wait for the pot to feel super light again.... always let it dry out completely before giving it the next thing in your water/feed/water/feed routine.