Try to get my first 29gls planted tank going so I got 2 bags flourish substrate from seachem at petsmart and lay it per instruction so I have good 2" of substrate flat base then I lay out a 20lbs topfin gravel and make some small hills here and there. on the hill I have 1 and 3/4" of gravel on top of the substrate and on the none hill i have about 1" of gravel. Should I have any issue for the plants if I plant in the hill? or is it to much gravel that the root wont get through? Did you guys wash the substrate before you put in your tank? Thank you.