With algae scrubbers, the key is flow and lighting
For a 150 gallon tank, a algae scrubber would need to be about 12 inches by 12 inches assuming it is lit from both sides with the correct amount of lighting. That would be 144 square inches of screen which would need about 500 gph of pressurized flow to force it through the tiny slit the screen also fits into. You will not get that from a drainage line unless you are putting around 1600 gph through your tank which is far to much for a fresh water set-up. You have to keep in mind, a scrubber will add at least some pressure to the line that supplys it.
If you read through the last link I posted it should a little more clear to you than how I must be explaining it in this thread
If you take your time to do the research FIRST, you can successfully set-up and keep ANY type of aquarium with ease.
"Not using a quarantine tank is like playing Russian roulette. Nobody wins the game, some people just get to play longer than others." - Anthony Calfo
Fishless Cycle Cycling with Fish Marine Aquarium Info
yep i see where you are coming from, that's why i have seen recommendations of running a dedicated pump for the scrubber alone, thanks for your help i'll just keep researching what other people have done
6ft Australian Fresh water turtle tank - 2 macleay river turtles, numerous guppy at varying stages of development.
5ft 150gal planted discus tank - 8 discus, 10 cardinal tetras, 10 rummnose, 6 albino cories, and breeding RCS in tank sump and just about everywhere everything done from scratch, filtration and stand tank