I used pk 13/14 and carload in my dwc without any issues, and I believe both are designed specifically for hydro. I quit doing dwc after my chaze (see link in signature) and chem city blues went tits up. I believe this happened because I was doing hydro and soil in the same tent and cross contaminated. I modeled all of my dwc grows after Seymour Buds Think Different and got 6 and 8 ounces off my first two plants using his model. He uses carbo load once he switches to flowering nutes. I've also Canadian Xpress' Superior Potash with good results as well. Hope this helps! And for my money, I wouldn't buy an LED without a secondary optic to help magnify and spread the light at the same time, like the blackstar chrome, Cidly Apollo, grow northern, hydrogrow, Bysen sp series, etc. I've ran all types and have gotten the best results consistently under the ones that have the secondary lens.