I have recently been using Dyna-Gro & I have fallen completely in love with everything they have, that I've tried (Grow, Bloom, Mag-Pro + Pro-Tekt.) If you were going to buy bulk nutrients then I think you could get by with a gallon(s) of Grow & a smaller supply of Bloom; like 1/2 gallon(s), etc. Like HB said, the only problem at all with DG nutrients is that the Bloom does not contain enough Nitrogen to keep a plant green/healthy throughout flowering... but then again- neither does anybody else's bloom/flower formulas IMO. Almost any brand of nutrient will work, assuming the pH is 'correct' and the NPK is at desirable levels relative to each other. DG is awesome; almost idiot proof, just add a bit of the Grow into flowering solutions. I favor DG, no question, over any Advanced nutrients product anymore (though I've encountered great results with their "Jungle Juice" formula (and it's a copy of GH's 3 part nutrient, so I assume that GH would also produce acceptable results.))
HomeBrewer- I use tapwater myself but I was just curious, have you/do you know if anyone has experienced calcium deficiency problems with Dyna Gro stuff?