Lighting in DIY grow box
I'm on my very first chili growing adventure (really, the first time I'm growing anything). I started out sowing two seeds each in 10 coconut pellets and kept them in a small lidded plastic box in my bathroom, where there's underfloor heating. So far, so good, 9 days in, 19 out of 20 seeds sprouted.
This weekend I built a grow box out of a cardboard moving box. Clad the inside with aluminum foil (including a lid), put the seedlings in small plastic cups and attached two fluorescent light tubes(?) about an inch away. Lid goes on top and air comes in via the moving box handles (holes on the sides). Temperature inside is roughly 23C.
After watching people on YouTube, I worry that there's not enough light. Im using two 8W tubes. I went low so I wouldn't have to worry too much about heat/confined space and associated fire hazard. It looks pretty bright to me, but is it way too little light? Seedlings are growing and look healthy, but it's only been 3 days at the most.
Also, roughly how often should I water them? I understand that they should pretty much dry out between waterings, but should it be roughly daily, weekly or something in between?
Any help is greatly appreciated!