Habitat - Indoor :: DIY tank filter keeps overflowing

[Munkee915]

So we upgraded our turtle to a larger tank last week and bought him one of those filter/rock combos but it didnt seem to cut it. I decided instead to build a DIY filter large enough to support whatever tank he may need in the future. I bought this pump (http://www.amazon.com/gp/product/B006M6 ... UTF8&psc=1) from amazon. It wouldnt fit in 4 inch pvc so i bought a 2 gallon bucket and lid from home depot along with fittings and hose and 1/2 pvc pipe. i have 1 pipe running into the tank on each side, then down and around the back to the bucket. In the bucket, i have the pump sitting at the bottom surrounded by pot scrubbers, the a layer of filter media (http://www.amazon.com/gp/product/B00BUF ... UTF8&psc=1) above it, the a layer of bio balls (http://www.amazon.com/gp/product/B000NR ... UTF8&psc=1) and ceramic rings (http://www.amazon.com/gp/product/B001CZ ... UTF8&psc=1) and above that a diy charcoal filter i made from 2 layers of filter media with charcoal (http://www.amazon.com/gp/product/B001CZ ... UTF8&psc=1) in between. When I hook it all up it seems to run fine but after about 15 minutes or so water starts to push out through the top of the lid. It seems like its pulling in more water than it can push out but i dont understand how that can be, shouldnt it just be pulling in as much water as it pushes out?

heres a pic of my filter layout if it helps:

[Insanity]

I have a few questions.
Where is your filter positioned in comparison to the tank?
What difference in height level is there?
What are the lengths of the pipes?
If I understand correctly, both the intake and output pipes are 1/2 inch diameter?

[steve]

This filter is inside the tank?

[VeipaCray]

Sounds like the pressure caused by the siphon that feeds the bucket was greater than the bucket to lid seal.

Most commercial canister filters have a o-ring between the canister body and top part with a very strong water tight seal between the two.