Is my ppm ok?

Water is wildly different one from location to the next.. What is good as a 500 ppm for me may not be for you.. Higher Temperature increases the need for water.. Judging from the look of your plants and without knowing where your water Started.. I'd dial back your nutrients to 3.5 drops per liter ha ha. Especially for the first few feedings. 75% of the problems on here are from Overfeeding and Overdoing things.. Have patience and learn to allow them to grow the way they want too. Plants grow themselves we are just the silly care takers who try to keep them alive.