water flow/powerhead questions

[salt creepette]

I know this is two questions in one, but here goes...

I am going to order some powerheads from online and I need to know how many/how strong of ones I need. I like the maxi jets. what I need them for is:

My 120 gallon (not set up yet): I own one maxijet 1200 right now (which is in my 30 gallon, flinging my chromis around the tank! funny visual, huh?? No, theyre used to it now, but it was funny at first!). I need to know how many/how strong (someone told me three 900's would work, is this right?)

and I also need to know how to arrange them the best in the tank for optimum flow.

Also while Im at it Im converting my freshwater undergravel (airstone driven) filter to powerheads. how powerful of ones do I need for that? what is the general flow rate/gallon rule of thumb?

[salt creepette]

oh yeah, the maxijet 400=106gph
the 600=160gph
the 900=230gph
the 1200=295gph

hope that helps (y'all prolly already know this stuff lol)

[jimcfar]

I personally wouldn't use an undergravel system for salt water any longer. I had lots of problems when I was doing that. The crushed coral caused some stability problems with water conditions. And somewhere, sometime you will have to actually clean it.

Recomend having 120 cut/drilled to run to a sump and use a large external pump for the return. Then use your powerheads inside the tank for water column.
You can then put all your stuff like heater and protein skimmer in the sump and it won't clutter your aquarium.

[salt creepette]

jimcfar, my 120 is predrilled and reefready with a sump. I do have questions re: water flow and powerheads, but....also...

it is my Freshwater 30 gallon that I want to use the powerheads for my UGF. see I told you it was a bit unrelated

[Rob_Reef_Keeper]

closed loop

[jimcfar]

OHHHHHHH probably if I read a little closer I woulda realized it was for the freshwater tank! LOL sorry!

[salt creepette]

Hey all, not trying to be pushy, but if anyone has any words of wisdom, please share... (see original question....)

[mnreefgeek]

I agree with Rob. Get the tank drilled for a closed loop.

[tdwyatt]

Hi SC.

For the undergrave filter in the freshwater tank, the 400's will do quite well, although depending on how meticulous you are on siphoning the gravel, etc, you can use the 800's and get a good flow through the tank, some of what you'll want will depend on whether you are keeping danio-types requiring lots of water circulation/movement or backwater types of fishes.

For the 120 SW/Reef, prolly will want to do one of several things, depending on your biotope you wish to emulate and whether you want to go all out, or do with what you have (and whether the tank is already established or not):

• 1200 's in the front corners about 2" from surface, another pair at about 3" from the bottom and your sump returns for the main water movement.
• even larger PH (again 1200 or larger pH's) pumps on the ends of a piece of 1"diameter PVC (May need adapters to take the ends down to the outlet size of the PH's). The pvc runs the length of the tank at about 2 to 3 inches of the substrate or at your desired height, and drilled every 10 to 20 cm with a 3 to 5 mm hole. This forms a manifold to increase current near the bottom or to circulate into your rockwork, use the main returns to create surface turbulance from the main pumps
• a second submersible pump (like a mag 12 or 18) in the sump or external pump plumbd from the sump that returns to a manifold inside the tank (flex hose from the pump up to the top edge where 1" pvc elbows go over to a manifold drilled to the specs above). A little dyi hint: make sure to drill a small 2mm hole in the pvc just under the surface with a downward bias to act as a siphon break when the power cuts off, Include threaded fittings in the manifold every foot or so to allow for directional adjustment.
• bore the glass and fit with bulkheads for a closed loop, of course, PH's would be redundant at this oint, although they could still be used to correct for dead spots through the tank.

Final placement of the PH's and which size for free-standing ones will depend on rock placement and whether or not you have a high energy biotope or lagoonal setting. Keep in mind that every PH or submersible pump you add will be putting heat into the tank, so if you use enough of them, and/or your placement of the tank has net heat gain (i.e., no a/c or in a basement, etc), you may need an evaporation tower or fans in the sump or a chiller to cool the tank if it is too warm.

HTH

[salt creepette]

wow, thats great (information) thanks tom! my tank is drilled with overflows and water is pumped back into the system via two 'tubes' which are adjustable. is that what 'closed loop' means?? If so, sounds like I can use those for water movement in addition to powerheads. I will save this info and use it for when I assemble my tank! I plan on having in the tank two tangs and misc other fish which I already have , and lots of soft corals like toadstools, leathers, xenia, zoos, mushrooms, from what I understand that is 'medium' water current requirements, right?