Please don't post ill advised information if you do not know...The problem in those pictures is not Gravity. A burn does not look like that picture. I use gravity for my plants @ 1/2 ml per gal. of H20 with 1/3 ferts and have never gotten a burn (using indicas).
Pig Let - What kind of filter do you have (brita....RO unit....ect)
My tap water is great (150 ppm) so I just de-chlorinate and mix. You can obtain a local water report with the ppms from your electrical/water company.
By using your filter you are taking the ca and mg away. Cannabis is a mg hog and judging by your pictures and set-up you have a mg def. Since my water already has some I usually put around 2ml per gallon with the Liquid Kharma. When introducing another fert into the mix I would go slow (5oz is too much at one time 5-6 weeks into the grow). I think a lot of people have a good equation to how much cal-mag you should use with filtered water.
One was 250 ppm of cal-mag (with 0ppm h20) and then add the rest of your ferts.
Because your sooo late into flowing, yellowing of leaves will happen as the plants slowly starts to swell and die. It uses up the leaves that are blocked by others and starts to use the others as food into the flush. If you have salt build ups, just flush. If your plant is in the 6th week and its an 8 week plant, then you will start to flush soon anyways.
Hope this helps
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