Hi Steve, are you also an Organic Grower? I only ask as I'm interested in finding out what difficulties you've encountered with salt build ups in your mediums? I grow organically myself with amended soil and occasional use of Biobizz Nutes during the Flowering period and have never suffered myself with salt build ups whether I water with 10% run off or not. I try not to have too much run off at all as I'm trying to feed my soil which in turn feeds my ladies so I'm not really looking to wash out any of the goodness that I've put in. I'm not saying you can't burn plants with organic nutrients as its very possible, just that they're far less likely to leave salt residues than chemical fertilisers that are salt derived. Im not trying to start an argument, just interested in other growers opinions as even after nearly 10years of growing im still always looking to learn. Cheers