Eyup lazyeye, you can use the boost from start of flower to the finish mate if you want with no probs, only reason people dont is cos of the price but if moneys not a prob why not, it will do nothin but good mate expecially usin it with the pk, canna recommends it. i was usin it at full strength while usin the pk worked a treat but only had the 250ml bottle so didnt last long, then i started usin sucanut(pure sugar cane) witch a few people say is all thats in the boost with a little extra. also the boost doesnt raise ec at all so no worry about usin at full strength at any time witch is handy if you dont take ec an ppms like me, so you dont worry about burn when usin with pk boosters..............but if you want to use boost or pk id go with just the pk, but both together is defo better!!
Plants are lookin nice too mate!!!!!