Preferred way to alternate flow between 2 powerheads in a reef tank?

[Djplus1]

Is there a preferred way to alternate flow between 2 powerheads in a reef tank? I have a 72 gallon bowfront RR tank running to two Sicce Voyager 3's position on each back corner about 3/4 of the way up, each aimed toward the center of the tank. I recently got an Apex Lite and have them powered every 5 minutes alternating the flow, which I assume gives the tank more of a tide effect. My question is, is it better to keep the flow how I have it or pulse it every 5 or 10 seconds alternating the flow for a more wave effect. Or something in between? Also, am I good with the two Sicce's where they are now or should I move them, or even add one or two more power heads to the mix?

 

 

I plan on keeping a mix of LPS and SPS corals and small reef fish.

[matt]

maybe this helps, or maybe it raises more questions for you...but...

 

I have a 46 bow. I decided to keep flow/pumps pretty simple and get a 'gyre' going. that is, my live rock has plenty of space behind it and my powerheads provide laminar flow from each bottom back corner (where placed) towards the top in the opposite back corner and hook around my rocks to the bowed front. i only run one pump at a time (other than a return pump), so my water swirls in one direction at a time....the 'gyre'. my plan is to alternate the current in each direction every few hours with the change in direction providing some randomization in addition to what I get off the rock. unfortunately, i haven't sprung for a controller to alternate the pumps just yet and i change which pump is running by hand ever day or two just to keep things interesting for my fish etc.

 

for your current set up, what do you see in flow patterns now? if it's pretty random etc, the extra wear on your pumps with more frequent on/off cycles may just shorten their life without any/much benefit to your inhabitants - 2 cents

[Djplus1]

maybe this helps, or maybe it raises more questions for you...but...

 

I have a 46 bow. I decided to keep flow/pumps pretty simple and get a 'gyre' going. that is, my live rock has plenty of space behind it and my powerheads provide laminar flow from each bottom back corner (where placed) towards the top in the opposite back corner and hook around my rocks to the bowed front. i only run one pump at a time (other than a return pump), so my water swirls in one direction at a time....the 'gyre'. my plan is to alternate the current in each direction every few hours with the change in direction providing some randomization in addition to what I get off the rock. unfortunately, i haven't sprung for a controller to alternate the pumps just yet and i change which pump is running by hand ever day or two just to keep things interesting for my fish etc.

 

for your current set up, what do you see in flow patterns now? if it's pretty random etc, the extra wear on your pumps with more frequent on/off cycles may just shorten their life without any/much benefit to your inhabitants - 2 cents

 

 

It seems that we have a similar flow going, just mine alternates for 5 minutes vs your hours. I also have plenty of room behind my rock wall (2"-4"). It seems the flow is random enough, but it's hard to tell since I only just put in two clowns and a Zoa frag and a star polyp frag this weekend (Live Rock doesn't move much, huh?) Dropping a few food bits in only results in a couple dead spots where I notice food settling, but that changes in the next 5 minutes so it's not too bad I guess.

[matt]

I think I've heard the sicce do better than some other pumps (ie koralia, or newer mjs) with short cycles...but I'm not that familiar. I'm obviously leaning towards a longer cycle time....so I'd say don't shorten what you have already. You'll get random flow as the currents change with each switch in pumps...I don't think you need constant switching or anything like that...but get yourself a 2nd and 3rd opinion...you'll feel better however you decide

 

Anyone else?

[icecool2]

I would just be worried about wear-and-tear on the pump from switching so often. There are plenty of controllable pumps out there that are designed for what you are describing too that can withstand the frequent on/off cycles.

[Der ABT]

Truthfully i dont really see that much benefit coming from switching them on and off so often, i think you will be fine with doing it every few hours if yuo really want....with two pumps going at the same time you will still some some random flow from the natural action of to flows hitting each other.

 

ive had good luck with koralia's (non controllable) on a wave timer..which i no longer use...besides the loud restart from the propeller starting the wrong way they still lasted 2 years or so...one even longer. i was using a red sea wavemaker...actually i need to sell that thing.

 

im using mp40s now and while they have varying flow rates i dont see any difference from before when i was just using some tunze non controllable pumps...i would just change their direction slightly every few days and that would stir some stuff up...

 

flow is flow...random or not...look at many shelfs in the reef...fairly constant flow over them.

[Djplus1]

Thanks all. Everyone here seems to be a great help. It's hard trying to figure out the "right" way to do something when everyone has a different "right" way. I guess as long as the fish and corals seem "happy" that's all that really matters.