Re:drilled vs non-drilled tanks

     I have a non-drilled 90 gallon planted tank, filtered by one 2015 Eheim 
     canister and one Hagen aquaclear 300.  I am a former saltwater tank keeper, 
     and I sold my wet-dry filter two years ago (I switched to freshwater 
     planted tanks because I wanted something more challenging! ;-).  I never 
     used my wet-dry in my freshwater tank, as I felt it was overkill.
     I had a hanging surface skimmer in my saltwater tank, but I don't miss it 
     because surface mulm isn't a problem in my planted tank.  Besides, it would 
     probably clog with the blooms and floating leaves from my huge swords and 
     apons.  The aquaclear is my "workhorse" filter, as plants produce a lot of 
     debris.  The aquaclear is a great mechanical filter, and very easy to 
     clean.  I removed the carbon bag and added a second foam block, for extra 
     filtration.  Mechanical filtration is a high priority for a planted tank, 
     in my opinion.
     The eheim is used primarily as a CO2 reactor.  I bubble CO2 directly into 
     the intake, and the outflow is on the opposite side of the tank.  I removed 
     all the floss filtration that came with the canister and filled it with 
     crushed lava rock--it's cheap, porous, and provides a lot of surface area 
     for bacteria to colonize.  Also, it does not clog with plant debris and I 
     don't have to clean it.  I'm sure the eheim provides some biological 
     filtration, but compared to the plants I believe it is insignificant.  
     There might be a gram or two of bacterial biomass in the canister, but 
     there are several kilos of plant biomass in the tank.  I think the ammonia 
     "demand" is greater from the plants than from the bacteria.  I know they 
     grow faster!
     My heater is obscured by my plants, and is near the intake for the 
     aquaclear and gets plenty of water flow.
     Bottom line?  My current system is easier to maintain, and is more quiet.  
     Also, if one of my filters fail (hard to imagine--eheims and hagens just 
     keep going and going; my eheim is 15 years old, and my hagen is 4), they 
     are easy to replace or repair.