MemberBerry nutrient burn/deficiency

Hi, seems nitrogen toxicity to me, you have got the claw (tip of the leaves curling down), really dark and shiny leaves ect. I think you have to flush properly your plant, wait for a week and than start feeding her again gradually. Hope this will help

Nutrient uptake depends on many aspects of your invigorate. If your plants are closer to a light or you’re doing a sea of green type of grow you can use less nutrient in your solution. as an example, using the general hydro feed 10 part feed chart I use half strength solution based on the “light” feeding schedule. However if you’re farther away from lights and now packing plants in tightly you can use a stronger solution. More is not always more

I'm going to agree with Chow_13 and Nugsery - you've got a nitrogen toxicity. Where I depart from Nugsery is in what to do about it. Your leaves are WAY too dark and it suggests the problem is fairly bad ... and now you're showing signs of a phosphorus deficiency in the edges of your leaves... So what I would recommend is for you to do a hard flush here. That means running 3x the pot volume of pH'd water through the pot - which, for you, would mean running 6 gallons of pH'd water through them. When they're dry, you can feed but only 1/2 strength at first and only the bloom nutes. Going forward, you can increase your bloom nutes to what you've been giving them but you might also consider adding a PK booster which will not only help with the deficiency but also serve to increase the bud size and density... Good luck!

Dark green and Shiny leaves, Leaf tips curling down. Yep that's nitrogen toxicity.

So long as your going onto your bloom formula now you will be fine. You may have done 1 week to long on the grow formula but its nothing to worry about. Also Berry strains and purple strains tend to have darker leaves.