Oh hell yeah man, for a 10 gal res it's TOTALLY worth it, no joke. I would recommend it for you for sure man. I have threads you can look at proving it's awesomeness. 5g = 1tsp roughly. My last grow I had 3 strains that didn't go over 1tsp per gallon. It really did work perfectly and you can also get a sample of +size which is a PK booster that works well. It works if used at the proper time. I 100% back the product up but for me switching to something cheaper might be the best route to go since I'll be upgrading things soon. I don't know though, I might use it for a while because I have their nutes completely dialed in and it's so damn easy. The only deficiency I've had is mag. The product contains cal/mag in great % but some of my plants are mag whores so I have to add a little more. They have RO version, tap water version, even nutes for coco or dirt (I have the V+B dirty version but haven't used it yet). I use the RO nutes with my tap water because my tap water is 100ppm (.7 scale)