DWC auto feed

Also -- any shift in formula (what you mix together) is best to do a full drain/refill to immediately shift to new formula, obviously. if you want it to be a slow transition, can do the top off over time and it'll slowly shift, too. e.g. you want to lower N but let it slowly reduce over a week or two, the latter option is viable. but, if reacting to a symptom or something, you want it to be more immediate and should do a drain and full refill.

You can top off, but the plant doesn't use up nutrients in equal rates. So, over time it can become out of balance compared to your formula... so, you can top off, but in some repeatedly consistent way you should do a full drain and re-fill. Whether that is once per week or once every 2 weeks etc.. i don't have the experience to tell you, but it's common sense. Wait for the plants to drink it down low and it's not too wasteful. One of the primary advantages of soilless / hydro is maintaining an optimal ratio and concentration of nutrients around the roots so that everything is readily available and does not impede each other. So, if your formula is good, i'd never top-off with water-only. I'd always try to maintain the target ratio and concentration your formula provides, because that's the whole point of hydro/soilless.

in an ideal world, youd be adding a consistent input in reality, depending on your measurements you will be adjusting your daily touchpoint as needed...until a solution swap as indicated below. if you trust your nutrient vendor, then a clean swap weekly per instructions

I grow DWC. In between feedings, when you change your reservoir solution once a week, top off with plain water only in veg and flower. If you continue to feed with every daily watering, you could create a very toxic solution for your plant.

PS : not DWC but same ; take a look ;) growdiaries.com/diaries/146329-grow-journal-by-selkot

Hey 👋 You can definitely count on the DWC during flowering; you'll just need to fill the reservoir with water and your nutrients (only minerals, otherwise you'll block the system with organic matter) more often than during vegetation. Remember to clean the tanks and reservoir once a week to prevent limescale and mold. If you see nematodes, add a little bleach. enjoy 😊