So I have an extra AC70 power head (400gph) laying around so I figured I would try putting it in my new AP24. I saw some DIYs that have tubing running along the top of the tank with nozzles, and I think that is the best idea. I am thinking 2 nozzles in the front, but I am not sure of the best way to plumb them. Which of these designs will work the best? Or is there a better way to do it? Also, if anyone has done this before, what is the best way to get the tubing to stay along the rim?

I would reconsider the choice in PH. It looks as if the AC70 uses 20w. Depending on what your other return pump is, it could cause heat issues.

Also, I know they wouldn't function as a return pump, but you could get the same flow out of a single Koralia 1 or two Koralia Nanos using much less wattage. Plus you would get the ramdomized flow without the extra pipe in the tank.

I had planned on only keeping about 1/2 of it submerged to minimize heat exchange. I guess I could get a couple koralia nano..I dont like how the look in the tank though is the only thing.

I think you would be running a risk running it half submerged. Sounds like a chance of burning up the motor, starting a fire, or both.

What look dont you like in the tank?

I dont like how a koralia stuck on the sides of the tank look. I guess I didnt think about burning the motor out half submerging it...that is a good point though. I guess I should just stick with koralia...

You can stick them on your false wall inside the tank.

Too much heat, IMO.