Click on a thumbnail picture below to see the full size version. 2 Entries. Tuesday, February 6 View Page Playing with grow tent and light finding out the hard way anything above about 320 ppfd is too strong   Tuesday, February 6 View Page Testing grow light and tent, these girls are 21 days old, but I had to find out the hard way that 300 ppfd is enough, 450 and 600 where causing my problems, ill run a new batch from start with the 300 setting and hopefully with wont be so crappy looking