Help with DIY 3 drawer filter

[oddballfishlover]

I am looking to start building a 3 drawer filter for my 50 gallon aquarium. It will be housed in a 30 gallon aquarium under the stand. My tank is not drilled and would prefer not to. I am wondering if there is any way to hook a system like this to undergravel filter plates. I have large rocks as aggregate in my tank and have a hard time cleaning all of the waste from under them. I think that an undergravel system would help with this but would like to make it work with the 3 drawer tower filter if possible. If anyone has any input on this, it would be appreciated. thanks