20/4 is perfect.That,s what joint doctor recommend.But 100 Watt are much to low,you need 50.000 Lumen and this you got by 400 watt sodium steam light.100 Watt are ca. 12.000 Lumen.For temperature,they are absolutly not sensitivelyt.For first 17 days you need 20/4 blue light Neon tube (or sun...