can someone help me please?

You need to form a plan and take action then stop. You need a specific plan of action then it takes time to see a recovery too. I don't want to keep rethinking it all so if you want help from me please outline the plan *you* want to take and I will hear it through if you want. I think you need a nutrient that you can use with more ppm because the plants are eating up something acidic from your nutrients, likely Nitrogen, and it will swing your pH up. Although pH drift in a reservoir is not the shock of going from 6.1 pH to 5.5 in a few seconds using Phosphoric Acid. The plants need some good nutrients and they need stable pH. Find a plan to get you there.

I don't mean to annoy you. I have thrown a lot of money out because I was too quick to listen someone telling me I should do something that turned out to be useless or harmful. I would be foolish to continue to not ask questions. You can stop helping any time you want and I won't even hold it against you.I am grateful for the guidance you did give me.

As for the plan I have been thinking about it all day. I am heading to Lowes to see if their ro water has a better pH. I am then going to prepare a gallon of php at full strength and moniter readings for 24 hours. 12 hours without medium and 12 hours with medium just so I can cancel out medium as a problem. If everything is stable I will flush and clean set up and run in plain phed water until nutrients are mixed or overnight to be sure medium is flushed well( will check ppm before and after just cause I want to know). Add plant to test and watch to see what happens while taking measurements and nothing else until I see change. if change for worse I will flush and switch to GH trio that just came and see what happens with different nutrients. Is that a proper plan?

I'm not getting annoyed I have to keep sounding stern or I think you won't take it seriously. Your list involves too much doing I think you should just change the reservoir out to flora then let them be. I only recommended AN because you didn't have nutrients on hand. I think you should choose a mixture of Flora and leave those plants be for a week at least, a good strong mixture that won't have them eating all the Nitrogen and sending the pH sky rocketing. DWC is awesome the growth rate is amazing and so is the recovery rate but they need consistency.

FloraMicro (5-0-1), Flora Grow (2-1-6), FloraBloom (0-5-4) is a much better formula to work with in my opinion also it doesn't have pH stabilizers so we can mix at will. I tried to find the ingredients because I was also thinking you could use Cal Mag Plus instead of the floramicro and use it with the FloraGrow for a really great ratio but I was worried about added Calcium Magnesium. Regarding the perfect ratio I have a link, a good one. I have followed fatman's advice for years as in my opinion he know his shit so pay close attention to his answers. After you decide on a ratio you should rethink what I said about using Cal Mag Plus, it lowers the Nitrogen from 5 to 2 and it has all the traces. So we can take an action that has plenty of N still but reduces it by at least half of what you tried before so likely no burning.
https://www.rollitup.org/t/lucas-formula-recipe-from-scratch-really.268790/page-2

When I said leave them be for a week I didn't mean reservoir pH and changes. I meant nothing extra just nutes and light

jj also I searched pH 8 isn't abnormal for reverse osmosis water just for me. Mine goes up to 7.3 sometimes but for example it is 6.9 right now. If you want to grab some water from those machines to avoid having to pH down that is sound logic for plants that aren't super healthy. Generally I'd say just pH down it.

Contact dynagrow if you are interested. You can get a quart of foilage pro, quart of protekt, pint of bloom, and a pint of root hormone for $19.

The foilage pro is a little higher in N. It is good stuff.