No I never used kelp meal. I stick to what works for me. I have no problems with the mix I use. They root like it's a race to fill the container.but if you want to try Kelp meal it's up to you. No growing method is perfect and what works for me might not work for you. So play with it and make it your own. A friend of mine said to me once, if what you do works for you, dont change it. It's the best way to avoid problems!