Nice overview. I would also recommend BACI's hydroponic FAQs for more detailed information. These are available by doing a search in this forum for "FAQ".

Phosphorous is locked up by the pH. It's in the soil but until you drop the pH a bit, it shows as lacking. That's why they fertilize with it....so the plant will find it readily available. If you set up an environment that the soil microbes can really get going in, then the phosphorous will be unlocked. If I add anything when I plant a potted item, it's some Rocket Fuel by Gardenville. Just a teaspoon so the plant has some help until the soil relationships are set up. Too much and it could actually slow down the microbes. Organic matter is the big key to our soils. We have so little of it that it sticks together. Every time you have plant debris leave you area, you've lost the nutrients that the plant used in those leaves and branches. If you don't put that back (and a little more for next years growth), you deplete the soil. But fertilizer alone won't fix the problem. You have to return the organic matter of the leaves and branches too.......hence compost should be added. Working the land properly is much more difficult than plowing, fertilizing and spraying pests. It requires close monitoring of the soil and rotating animals and plants around to keep everything at it's peak. Even weeds have their place in this dance as do insects. Chemicals won't fix the problem completely but sweat and smarts will.

I just went out today and bought a 7-3-5 fertilizer which also contains some miner elements. Further, I bought molasses - just maybe the wrong one, i'll check that in a separate thread! Rhizo, with regard to leaf cupping, I can rule out lack of sunlight and air circulation. At our current shadow temperatures of 27 degrees, that takes a little less than 48 hours. Is there a way to check upon excess moisture in the pots? Would a picture of a root ball help? Normally, I water them when their soil is bone dry and their leaves feel week 3 hours after the sun went down. And could you recommend me a potting mix ration from the materials I have at hand - commercial potting soil, perlite - please? I also have some coconut choir and vermiculite at hand but that might be counterproductive ;). Now, I just need to see what I can do against those mites, couldn't find fish oil or f.oil. fertilizer in any store today. @floral_uk Visual appealing is nice to have but I am more after the taste. They lost strongly smell since the symptoms emerged, now I hold back from plucking them as I don't want to weaken them further :(. So, not even caprese..

Grace, this is not BS. I have BS on my medallion and Queen Elizabeth. First it is black spots but they are always accompanied by a yellow coloring around it. Then it will turn yellow and fall off. This stays like that. Still same leaves and then gone. I was very puzzle by this and this is what I think. I could be wrong but could be right. Due to heavy downpours of rain. Maybe it got bruise. And the bruise was repaired by the rose immunity...I don't know. I agreed with Perma n Posies, environment stress and it repaired itself. I can't find marks like that on Google or anything. I try to post a pic but Houzz won't let me. I found 2 leaves but it looks really healthy but deep inside is markings. You can't tell Bec the leave also became dark green. Jin I just saw that one leave in first pic . It is very dark green colour. It is still there. The pic that I just posted 5 hours ago.