A combination of both with with the primary light leading toward 3700 in flower. So if you can install 2 lights then it would be the best IMO. Ex. 1-400 watt hps and 1-250 watt mh housed in a cool tube, etc..
If you can only get 1 light, 1 ballast then get hps. If you have the money then get a switchable ballast
growbe Reviewed by growbe on . flowering spectrum what spectrum should i use to flower in? or can i flower in any and you just get better results in a different one? ex. 3700k 4500k 5500k 6500k 6700k Rating: 5