Need some advice! Roots coming out the bottom

I'm having some issues with a 2 week old plant that i can't seem to figure out what is going on, at 1 week old a couple roots we're already starting to show out of the bottom of the solo cups, strain is from BC bud depot Girl Scout Cookie. Running on a 20/4 light schedule with 1 100 watt led blackstar light. Watering schedule every 4-5 days 200 ml of R/O Water at 200 ish ppm. Grow medium is fox farms happy frog with about 30% perilite mixed in. Ever since the first true leaves started to show they have been curling down like you can see in the picture. I'm pretty certain I'm not over watering. Any help will be greatly appreciated thanks!

R/O Water at 200 ish ppm. Grow medium is fox farms happy frog

ro water is 0 or a little higher fox farm soil is hot for seed starting
never had luck starting seeds in fox farm look like your also