A couple Newbie Power Head Questions

[sevise]

If everything goes to plan I will begin filling my 120AGA tommarow afternoon.

The other day I put my 4 MaxiJet 1200s in my tank just for kicks. Yesterday when I woke up they had all fallen down. Is there a general rpoblem with suction cup failure or is it just because they weren't submereged?

If I want a PH to agitate the surface, should the head be just below the surface or deeper and pointing up more?

How many PHs should I use on the surface of a 120gal 24x48 surface area?

 

[malkore]

they stick better when submerged.
i have mine pointed up to agitate teh surface.

Not sure on the 1200's what thier gph is...but you want at least 10 x per hour on a reef tank. so at least 1200gph on your tank.
if you're using a sump, you can include the return pump's gph too.
On my 40gallon I have 2 900's and a 600...somewhere close to 16 x per hour turnover.

 

[phases99]

They will definetely stick better when submerged. I use the hang on clips for my maxijets as suction cups will eventually come loose.