Hi enzo, thanks for the post. I have the in-take and out-take fans piping thingy going out, I thought this would be good for the flow of the leaves? I also have a small fan working higher up but.... I don't see how it could be the pipe as two are absolutely fine... It's only the other two with problems... What do you think? I am just waiting a few hours for my new hard water to settle before i put the Epsom salts in. I'm thinking I'm gonna add 1 teaspoon to two gallon pot. Ph it to 6.0 and add small dose of canna a and b and give them all a slightly bigger than normal feed?? Maybe 3 plastic cups rather than two? ......