i have this sump i got from dvs1 (phil) and its 20"Lx9"Wx16"H.anyway he has water level marked on it.so my question is how much water would have to go in the sump before i fire it up? i have experimented with it using to fluval houses (one was not enough,two worked good)even though i had to adjust the flow.but what i noticed is the water level in the tank drop and hold steady.i dont know if i should add water to the sump to bring up the tank level?its kind of confusing i never was good at math lol.thanks



