GH flora? as in flora series? GH offers a variety of products with the title "flora", but i have used both flora series and floranova, flora series is probably the best 3 part out there, as for floranova its a hybrid organic/chemical nutrient one part, very easy to use, no brainer, as per yeild i would say flora series because you can fine tune it to your specific application, on the other hand floranova will give you comparable results with less thought