first try

LOL, way too open-ended to give a short and sweet answer... read if you want... First, relax. You are overthinking things. You need some adjustments to your perception of cause/effect. You don't build buds by changing formulas. you don't force-feed plants like foie gras. Nutrient intake is an active process. The key is availability around the roots, not necessarily providing it in proportions of use within the plant. An important distinction. So, the goal of fertilization isn't playing mad scientist week to week to maximize results. You want to provid a consistent, full-spectrum of nutrition at ratios and concentrations that don't impede each other while also providing enough for the plant to grab as needed. The exact dynamics are a bit different between soil and soilless/hydro, but theoverall goal is the same. Soil involves guessing how much is provided by amendments on the soil and you ramping up supplementation through fertilization as time passes. Definitely looks like a Nitrogen deficiency creeping up the plant. I cannot see the rust spots, but if they are rust spots by themselves, that points toward a calcium deficiency. if irregular spots coincide with interveinal chlorosis, it is Mg deficiency. Important to note that despite common vernacular, Ca and Mg are wholey different elements of nutrition. People erroneously lump them together despite both having unique symptoms and being different nutritional elements. It is merely coincidence there's a common product out there called 'cal-mag'. it's not the only option, though. Google image search a "marijuana leaf symptom chart" -- i like the one stamped with "jorge cervantes" name. Look for a high resolution option you can easily zoom in clearly. You may need to ask questions, but referencing and gaining familiarity will greatly speed up the learning curve. You'll see that symptoms are not discrete. You need more than visible symptoms to diagnose most problems. Not only that, you can 'lockout' elements (layman's version of element) of nutrients. Incorrect pH or an imbalance of some nutrients being fed too highly can lock out other nutrients -- goes back to the goal of maintaining readily availble nutrition around the roots stated previously. Usually this sort of cause of problems results in a multitude of confusing symptoms, that i don't think is the case here. Irrigation is another concern of new growers. Fixing irrigation habits can fix many problems too, though i think you do have a N deficiency, and if your description of rust spots is accurate, Ca too based on your feeding regimen and happyfrog soil being pretty light on amendments and needing supplemental fertilization pretty early on compared to a hotter soil. Something like fox farm ocean forest can keep plants well-fed for 8 weeks by comparison -- neither is necessarily better or worse, just dynamics of the products. 1) fully saturate with minimal runoff just to ensure full saturation. In soil, runoff is throwing money away unless doing so to correct a specific problem. 2) wait for appropriate dryback -- triggered by loss of weight or depth of dryness you feel in top of soil. If not doing that, amend irrigation habits and it will avoid root zone problems and complications regarding nutrition. Soilless context has some different needs, but this is all yo need to do for soil. How often you add fertilizer completely depends on how much you give each time... that you can work out through trial and error as well as looking at what other people do while using similar fertilzier products.. if you only fertilize 1/week, you will be mixing at a higher concentration than someone that fertilizers more frequently. Never partially water. Never water superficially. The volume required is learned in hindsight and not a pre-ordained thing. The time between irrigations is variable as it drinks faster over time. Again, keep it simple and don't make it complicated. Observe dryback, trigger irrigation - doesn't require any thought. If proper habits ever causes a droopy plant, it is 100% the fault of the soil constitution. Add more perlite or similar next time -- not the end of the world in the meantime. Soil takes a lot of familiarity to devise when to supplement what in your fertilization, so there's no 1 answer for you. Your current fertilization is definitely not providing enough, we can see that. Now it's a matter of making some adjustments and observing results. Don't wildly change everything constantly or you won't learn anything to avoid the same problems next time. Take notes of when you added various nutrition to fertilization and how you ramped up concentration etc etc.. This will help you assess and adjust your methods next grow. So, definitely need more N than you gave before and more Ca. The best route would be to add these without impacting the other portions of nutrtition. This isn't always possible, but minimize the impact on other elements as best you can when making such adjustments in response to a problem. You don't want to exacerbate it by causing more problems. Fertilization isn't just what you did last irrigation or even the last several days. it is the culmination of all choices from day 1. IF you feed heavy early, you need less later etc etc. and that's per nutritional element - N/P/K/Ca/Mg/S are all important at all times. It may be more chaotic your first cycle or two, but the more consisntent you can be about your fertilizaation, the easier it is to adjust to what you observe the next time. If you want to hit the easy button, go soilless. cocoforcannabis.come is a great source for info that mostly caters to soilless growing, but many things will be useful for soil too. I don't recommend coco coir, but it's not horrible, either. When you are responsible for 100% of nutrition needs through fertilization, it takes a lot of the guesswork out of it. You can hit the ground running with high quality plants day 1 if receptive to instruction. Soil may take a bit more trial and error to figure it out. There are positives to soil growing, too. Super soils can require mnimal to no fertilization which is pretty cool and less time mixing shit up. So, this isn't trying to dissuade you,but is also true.. you can apply a known formula and get expected results with soilless/hydro, immediately. If you change products or add products to the fertilization, you may need to revise the process again. Different soils come with different levels of nutrition, but once you go through the process once, it's much easier each time after that. You may find you need slightly different formula in flower vs vege, but as a whole you won't wildly change fertilization day-to-day. The plant will tell you everything you need to know over time. Deficiencies and toxicities result when things are out of balance - results of rate of use vs availability over time. Changing temps, rh, and light intensity can all make for differences in metabolism, too. Don't try to min/max nutrition.. .it's more about a happy zone of concentration that provides what is neded over months of time. What works for a few days but leads to inevitable problems is not in balance. spiking or blasting it with nutrients at various points often doesn't do what people promise or believe. Maintain health, push upper levels but dial back when you see toxicities rise over time... good results are inevitable, if you do that.