NP on the suggestions. Also thx in return for the link to that tee - I haven't seen one of those and I am always on Champion's site
Seems that it would be fine to run the tee for the input as well as the ouput. The restriction in the flow would be negligble, only a little due to the fact that you are introducing a tee. I wouldn't have much hesitation doing that. I'm assuming you would then be bringing down 2 1" feeds. But I would not use an Undergravel (I think that's what you were suggesting). And my preference would be an overflow with a sump which feeds into the Nu-clears.
- I really like those Nu-Clears - they are really great for post sump filteration. I.e. let the sump collect the water via Overflow (skimming) then pump it through these things and you could support one huge bio-load. I'd recommend loading one of them with 1 to 3 litres of Eheim Ehifasubstrat
This stuff has a huge amount of surface area. In addition the particulate filters by Nu-Clear are going to take any free-floating particles out ('water polishing') - and the media is washable.