Should we SLOW our FLOW at night time in our reef tanks? Are you?

BRS

Do you lower your water flow at night time for your corals/fish?

  • YES

    Votes: 233 36.2%
  • NO

    Votes: 398 61.9%
  • Other (please explain)

    Votes: 12 1.9%

  • Total voters
    643

revhtree

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WOAH, slow your flow there partner!

There is the idea that ocean currents are more calm and night and so lower flow at night in our reef tanks better simulates the natural habit of corals. Does it matter for all of our corals and livestock or just the shallow water corals? Are you buying it?

Do you think you should lower the flow in your reef aquarium at night time?

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waterboys

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Not sure if it’s considering lowering the flow, but I do lower what I guess is called turbulence. Not sure if it’s the appropriate thing to do but I have my left powerhead run from midnight to 4 pm and then my right powerhead run from 8 am to midnight. So they are both running at the same time for 8 hours a day and only one running for the other 16 hours. My thought is that I can’t change the actual power being emitted from a single powerhead but I can vary the direction. I don’t have any coral yet so I have no idea if this would be a good idea long term or not.
 

Dakota_reef

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At night the waves are actually larger and more frequent because the moon has more pull on the ocean then the sun does. So in my opinion should just be the same all day.
As far as I know the Moon/Sun affect the tides, not necessarily the currents/surge. Most currents/surge can be affected by weather, but generally at night, they are calmer.
 

SaltyT

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My MP40s switch to Lagoon mode overnight, but I don't really have a good reason for it. Since my corals aren't fully extended when the lights are off I figure why not give the power heads a little break ¯\_(ツ)_/¯
 

immaman2011

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As far as I know the Moon/Sun affect the tides, not necessarily the currents/surge. Most currents/surge can be affected by weather, but generally at night, they are calmer.
It's not a big enough difference to lower or higher flow because fish will have hides and rocks and plants to hide in. And I'm sure corals won't care of the difference, mine are growing nicely and I keep flow the same. Fish don't seem to care either they just float in low flow areas.
 

LordofCinder

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I keep the flow low during the day for my clams, but I crank it up at night. I believe a tank is healthier with higher flow.

And I do believe that waves at night are the same as day, if not more, and then of course there are ocean storms which can last for hours up to days.
 

immaman2011

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Moon affects tide not waves directly.
Research shows the ocean actually moves more violently at night. The reason why waves move more during the day is because there is more human activity on the ocean during the day. But naturally at night the ocean moves with stronger force.
 

Lavey29

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Research shows the ocean actually moves more violently at night. The reason why waves move more during the day is because there is more human activity on the ocean during the day. But naturally at night the ocean moves with stronger force.
Interesting, I just got back from Maui and after a week and 300 beers on the balcony, it sure looked like everything was calmer overnight.
 

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T-J

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Waves get stronger at night since the distance between the Earth and moon decreases and gravitational force increases.
You've said this twice now in the first 10 comments of this thread. We get what your opinion is. :zipper-mouth-face:

Flow/currents may/may not change based on location. It really depends on the specific reef your looking at more than anything.

I scuba dive, and I've been on the same reef day/night and I've noticed significantly calmer flow at night than during the day. I've also noticed no noticeable change between day/night.

Having said all of that, I personally slow my flow in my tank down at night, and switch to lagoon mode. Extended polyps have plenty of movement still, but it give all of my fish a break and allows my CUC an opportunity to easily do its job.
 

Reeffraff

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Nearshore wind-driven waves typically peak in the afternoon and reduce at night due to reduced seabreeze from a breakdown of the thermal gradient between land and sea that develops as the land heats up during the day while the air temp above the ocean changes little. Tidal flow is primarily the result of moon phase and thus is not related to the time of day (i.e. you can have strong tidal flow at night or during the day).
The argument for reducing flow in a reef tank at night is that it would make it easier for corals to catch food when feeding polyps are extended. That said, I've not noticed any discernable difference in my reef tank tanks in terms of coral health/growth by reducing pump velocity at night. If you are someone who broadcast feeds corals, putting pumps in 'feed mode' for a few mins is more than sufficient.
 

immaman2011

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Interesting, I just got back from Maui and after a week and 300 beers on the balcony, it sure looked like everything was calmer overnight.
Gravity is stronger at night just because there aren't any high or strong waves doesn't mean the water doesn't move with more force. Gravity is going to be working against the waves which is why you see less of them. More pressure means more forceful flow at night.
 

immaman2011

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You've said this twice now in the first 10 comments of this thread. We get what your opinion is. :zipper-mouth-face:

Flow/currents may/may not change based on location. It really depends on the specific reef your looking at more than anything.

I scuba dive, and I've been on the same reef day/night and I've noticed significantly calmer flow at night than during the day. I've also noticed no noticeable change between day/night.

Having said all of that, I personally slow my flow in my tank down at night, and switch to lagoon mode. Extended polyps have plenty of movement still, but it give all of my fish a break and allows my CUC an opportunity to easily do its job.
Just trying to explain how gravity works with the ocean at night.
 
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