Test it out many times by unplugging your return pump. The last thing you want is water overflowing the sump during a power failure, especially in an apartment.
I also calculated. 1" of water (3" just to be safe) in the tank is about 28g. My sump is about 80g and half-filled. Which is more than enough space to hold 28g of backsiphoned water.
If you just had a U made with elbows, the water level in the overflow would fill up to the top of the pipe, then the U would fill with water and siphon the overflow down to the bottom of the U.
So basically, unless you have a tee with a cap and a hole drilled in the top, it'll do this:
SPLASH SPLASH SPLASH until water fills overflow
LOUD RUSHING WATER NOISE followed by GURGLE GURGLE GURGLE when the siphon breaks.
and repeat.
In other news, I got the lighting already. Its 8 bulbs of T5 39W.
As promised, here is the full tank shot.
If you noticed, I have a light down at the sump too. Thats because my palma polli and lapradei are in there as a temp "refugium" since they are still small.
Thanks to those MFK members who recommanded this mod to make the intake much MUCH quieter!
Close up of the Durso
I added a control valve used for airline tubing for fine-tuning the amount of air entering.
Top view of the overflow.
I added stones to weigh down the PVC mesh onto the Eggcrate to prevent my ropefish from slipping through (sneaky bastard!). That way I don't have to silicone the mesh onto the eggcrate and wait for curing time.
NIce tank upgrade! ANy plans on adding any mid-top level swimmers? Like some nice wc kelberi since your in sg and they seem to be all over the place. They would look great in there