So I've never had this problem because i never thought they would get that tall. I know literally nothing about them and its the most basic co2 system you can think of. I'm pretty sure its the wisteria that's going crazy. So whats the best way, place to trim down plants. Also, in one corner of the tank, opposite of the filter out takes and the co2 thing, they are getting a little yellow. I haven't used root tabs for a while, because everything is growing like weeds.