either get some bloom nutes or start flushing with just straight ph'd h2o or distilled h2o when u start to flower.. seems like ag tabs are for more for vegging. im bout to switch over to flower here soon, and my past 2 attempts have been using ag tabs throughout.. gonna try just ph'd water flushes weekly next time here instead of those ag tabs. oh and at my w.mart i havnt seen anything, however i have found a great selection of lots of necessities on amazon.com! lol random i thought but found net pots, all kinds of nutes and other shit. good luck, ill post on how just water seems to be working over using ag nute tabs for flowerin, my babies are 4-5 weeks vegd from germination on ph'd and little bit of nutes here and there. theyve nicely filled in and got real bushy. all growth is very green and seems like they explode another few inches everyday. seems to love the ag tabs to veg, got so much damn like salt build up or whatev that shit is tho