White Widow Auto - 00 Seeds - Hydro

Yes, I had this issue as well, she grew up big and healthy anyway. The first couple leaves often come out weird. In my case, I believe it was because I added nutes to my DWC too soon. I've since learned to wait until the cotyledons begin yellowing before I add nutes.

Algae will defintely start gorwing over 90-100+ days.. or even a shorter run with an autoflower. That'll steal O2 and N at the least. Roots aren't a fan of light, either.

if you have a swap out and clean system, this may not be a big deal, if cleaned often enough, but roots still don't like light and however that might impact your grow remains.

Tape some aluminum foil around it? cardboard.. anything. spray paint the outside black might work?

You need to take the grow nutes out in flower and just use the flower nutes. Ph needs to be set at 6.2 or 6.3 Dutch nutrient formula is great for hydro grows or canna aqua. The real dark AN ph crap is really not the best. Your ec should be about 1.6 to 1.8. Dont add cal/mg unless you see they need it. Cheers