Add to lights, or get a different light?

(Going to simplify) S1000 is 100w, you want around 80-150w per plant if you want to push growth to a strong level. Flowering bud requires much more complex proteins than leaves. SP1000 does 570ppfd @ 18". On the hottest day with clear blue skies, you get roughly 1500ppfd, the most a plant can use with co2 before you get diminished returns is around 2000ppfd. I personally run a (5x5 flowering) 400w in a 4x4 tent, this gets 1400ppfd at 18". You can have too much heat radiation, but you can never have too much light, just keep adding what you can when you can if it's financial :) every little helps and don't be afraid to mix it up. the bp4000 is an excellent price right now at 309, save a little cash and get a substantial light