View Full Version : Less flow at night?

08/24/2006, 12:11 AM
Makes sense since the ocean is generally more calm at night. Do you guys turn your CL off or in some other way make things more calm at night? Even if I turned off the CL, I would still have the tunze streams and return flow coming in. Just wonder if that flow at night makes any difference to the corals.

08/24/2006, 01:01 AM
I too am waiting for an answer on this one. I have always had a wavemaker or, now a Controller, to turn off all but one powerhead and the return during the night. Lately, I am wondering if it makes a difference. Maybe my SPS's would do better if I left everything on at night. Anyone have some thoughts on this topic?


08/24/2006, 02:01 AM
why dont you try just turning down your streams say maybe 50% and have them alternate slower(more time in between). If you have a controller you acn do that.

08/24/2006, 03:04 AM
not sure but i think less flow will lower your already low ph at night, i wouldn't turn it down too much.

08/24/2006, 03:23 AM
is it really calmer at night? I think it might be just as high of flow at night then in the daytime.

Lowering your flow WILL NOT lower your pH. crazy kids =)

Peter Eichler
08/24/2006, 03:28 AM
<a href=showthread.php?s=&postid=8002145#post8002145 target=_blank>Originally posted</a> by Kinetic
is it really calmer at night? I think it might be just as high of flow at night then in the daytime.

Lowering your flow WILL NOT lower your pH. crazy kids =)

It's not really calmer IME and I'm not sure why so many people seem to think it is. Lowering your flow will decrease gas exchange at the surface of your water and could certainly aid in lowering your PH.

08/24/2006, 03:28 AM
u don;t think so? it does in my system at least since i have one power head pushing the surface water. might be something else...

08/24/2006, 04:11 AM
Good idea:

Run a frag tank with your main system, have it on an opposite photo period, and then the time in between, fill it with a refugium light. Also keep the flow at max all the time. I think that'd be a good combo for a healthy tank ;)

08/24/2006, 04:46 AM
IMO the sea is not any calmer at night, especially under the surface, it's not like rivers stop flowing and currents stop moving during the night in the ocean.

Personally i leave all my equipment on 100% of the time...

08/24/2006, 06:43 AM
Anyone seen any hard data on this, are the currents calmer during night?

I have slightly lower circulation during nights, but my daytime flow is very high, so the night flow is still quite high too.

08/24/2006, 09:03 AM
Never been diving at nght but "they" say it's no calmer at night. Makes me wonder why these wavemaker/ controler companies make a night time feature that slows down pumps then? :confused:

I have a night mode on my wavemaster pro that I never use.

08/24/2006, 09:25 AM
A couple of good articles to read on flow: Advanced Aquarist's Online Magazine; June 2006 and August 2006. Go to: www.reefs.org

AAOM link has the articles.

08/24/2006, 12:39 PM
I HAVE been diving at nite....red sea, caribibean, indian ocean...
The currents are just as strong at nite as in the daytime!
Under a full moon in the red sea, the current was so strong one nite we had to abort the dive!

08/24/2006, 12:45 PM
Perhaps I thought it was more calm because when we get up early to go fishing, it is real glassy. Maybe the wind had more to do with that. I see nothing in Steve Tyree's article on flow at reefs.org that indicates that day or night makes a big difference. In fact, I think he indicates that there is greater gravitational pull when the moon is out then when the sun is out, thus creating more tidal movement at night......new one on me.

08/24/2006, 12:45 PM
the ocean is not calmer at night. i have spent almost as many days on the water as i have on land over the past decade and i can tell you it is just as rough when the sun sets as it was during the day.

08/24/2006, 01:27 PM
I think they make it that way so that you can turn it down at night and let the fish relax.

08/24/2006, 01:29 PM
I'm always in the ocean fishing offshore and 75% of the time it is much calmer at night.

08/24/2006, 01:44 PM
maybe it depends on where you are and what the weather is like?

08/24/2006, 01:47 PM
i don't have less flow at night, because that is when your tank needs o2 the most, as photosynthesis has stopped, so decreasing flow would also decrease the gas exchange during its most important time.

Peter Eichler
08/24/2006, 02:07 PM
<a href=showthread.php?s=&postid=8004572#post8004572 target=_blank>Originally posted</a> by msuzuki126
I'm always in the ocean fishing offshore and 75% of the time it is much calmer at night.

The surface being calmer doesn't always mean there's less flow below the surface.