Powerhead positioning

Oh and another flow question! What we've read states you should position powerheads near the top but in most tanks that I've seen (other members, the LFS) have them about 2/3 of the way towards the bottom pointing up.
Is there something special that makes this configuration better? We couldn't do it this way because we've found the suction cups can't support the weight of the powerhead for more than a week or so, so we have to use the hanging clips which leave the powerheads at the top.

Allrighty. I guess it wouldn't be too tough to rig up some hooks to hang the things lower. We'll try that, thanks! Still curious about if it's enough/too much flow and if it will cancel flow out tho :)

Edited by clubbby - February 27 2012 at 10:14am

if its a reef tank, make that 20x from what i remember. Get two or three power heads and point one from the back right across the back and one one the back left pointing forward and both up. You wont cancel out flow, thats not going to happen unless you have some awesome wave harmonics in there lol. You will get patterned flows depending on your positions. Just play around with it until you get the pattern that works best for your tank, coral and fish.

I didn't read everything above so please forgive if I am repeating good advice from my friends.

I've experimented with all kinds of flow using the minimum number of powerheads. Two MJ1200's in in each back lower corner that tank could be just right. I'm not so sure about the new mods to make MJ's into propeller driven "stream pumps". I've never been impressed with small sized stream pumps. The current that the standard MJ1200 small nozzle creates is just right in my experience.

I set the suction cups backwards (see pic below) which makes it stay better(scrape the surface clean) or you can push the back corners of the powerheads into the sand or supported by rocks.

The two streams of water that hit in the middle top surface of the tank create a good turbulent vortex which swirls down and around to create as good of flow as possible.

Here are some pics of how to modify a MJ1200 with a secondary intake screen of Plastic Canvas sewn together with fishing line and super glue which makes it go longer before needing to be removed for cleaning.


Best placement angle


This 75 gal had two powerheads positioned on the sand in the back corners shooting up diagonally to the surface with a Poormans Wavemaker at the top back center sending streams alternating back and forth every 6 hours like the ocean tides. Everything did very well in this tank. Follow this link to the very ingenious MJ1200 Poormans Wavemaker, which is also found in the Reefkeeping Tips below.



Edited by Mark Peterson - February 28 2012 at 5:30pm