Hydroponics Question? 2 stages of growth (veg and almost flower) on one tank. Issue, or solvable?

You issue will be that your bigger olant will need more nutrient then your smaller one. A good 400ppm . Findind a middle will be hard. One will be underfed and one over fed.. so you'll have luckily the amount of nitrogen needed for the younger will become slightly more then as the flowering grow more . I assume you are asking becaus you run autoflower. So you'll have to seperate your nutes. By slightly raise the PK and jeeo the nitrogene stable and get you smaler plant used to a higher dose. Basivcly oush it slowly harder. So use something pretty flat in numbers. Just about how yihr smaller can handel and slowly raise ppm in solution every other days with pk boost.. its possible buy it has to be donne really gradually. The small plant will absorb more and more nitrogen and the tallest one less en less.