Turning power heads off at night?

[Codym808]

You need some flow at night. My bubble gum monster chalice and sun coral actively feed at night. Some acros extend way out as well, so some like nighttime and need flow.

+1 also helps to carry away waste

 

[Fourstars]

It depends on the type of thank. In an SPS tank the flow seems to tire the livestock, so I lower my flow at night, plus the CUC can work better. If it’s a lower turn over tank i’d Just leave it on.

 

[ca1ore]

I was under the impression that currents are more slowly affected by wind than the density of the air or temperature. Doesn't that mean that the wind could die down but currents persist to an extent?

I agree, doesn't really pass the common sense test. Ultimately it's all lay speculation though - fish seem more tired, are more muscular …… puhleeese. What does the data say?

 

[wesman42]

I agree, doesn't really pass the common sense test. Ultimately it's all lay speculation though - fish seem more tired, are more muscular …… puhleeese. What does the data say?

I agree! I'd imagine there's evidence for and evidence against....but if replicating the ocean as closely as possible is the goal then I'd like to see the data as well.

 

[Biocube32]

In my experience with the ocean and fishing, during the day its a lot more windy which causes the ocean to have choppy waves. The choppy waves make the water near shore and on the reef pretty rough.

At night time the winds die down and the ocean is more calm with a more gentle up and down movement of the water. The waves aren't breaking as hard over the reef and even the diving is a lot easier since you're not being thrown around and slammed. Not saying there is no current at night, but IME the ocean slightly calmer at night.

*Edit* Unless there's a storm rolling in, then the ocean is rough all day and night.

I agreee. Especially in the context that most coral reefs are near land or in shallow water. Sea breezes generated by land and heat do increase local wave action and water flow in the daytime. I think it is incorrect to assume that daytime coastal water flow is the same as nighttime. Now deepwater ocean, sure theres not much change between daytime and nightime flow. But anything within dozens of miles of a large body of land is almost definitely affected by daytime seabreezes that generate waves and flow in some way.

 

[ca1ore]

Also keep in mind that the trade winds in the tropics aren't as variable night/day than in the temperate zones ….. I think at the end of the day (pun intended) if you 'think' it makes sense to reduce flow at night, do it; if you don't, then don't. Doubt it's going to make much difference one way or t'other.

 

[Biocube32]

Also keep in mind that the trade winds in the tropics aren't as variable night/day than in the temperate zones ….. I think at the end of the day (pun intended) if you 'think' it makes sense to reduce flow at night, do it; if you don't, then don't. Doubt it's going to make much difference one way or t'other.

I mean trade winds exist but local variations and sea breezes persist and have a significant effect. I have been to the tropics and surfed there plenty and paid close attention to the wind. Wind is consistently calmer at night in coastal areas. This is readily verifiable. Google Nosara Costa rica weather forecast. This is a place well within the tropics and costa rica is a nation known for strong tropical trade winds. They have lots of windmills to generate electricity. Look at the hour by hour wind forecast and you will notice the coastal wind in nosara is almost always decreased at night.

 

[Hemmdog]

@bubbaque what do you do at night with your flow? I’ve been interested since you have great success with acros.

 

[ca1ore]

I mean trade winds exist but local variations and sea breezes persist and have a significant effect. I have been to the tropics and surfed there plenty and paid close attention to the wind. Wind is consistently calmer at night in coastal areas. This is readily verifiable. Google Nosara Costa rica weather forecast. This is a place well within the tropics and costa rica is a nation known for strong tropical trade winds. They have lots of windmills to generate electricity. Look at the hour by hour wind forecast and you will notice the coastal wind in nosara is almost always decreased at night.

My comment was a relative one, not an absolute one …..

 

[bubbaque]

@bubbaque what do you do at night with your flow? I’ve been interested since you have great success with acros.

I don’t do anything different for at night. I know some people turned them down for their fish but really the fish all go in a spot in the rocks to sleep.

 

[Tastee]

I run my Gyre on a cycle akin to a tidal cycle, on the completely baseless assumption this may be good (-: It does give me some variability and the fish and corals seem to be ok with it. At midnight I run a Gyre (reverse) flow to help move detritus around from an area that otherwise doesn’t get much flow - figure this is a good time to move it and let the CUC get interested.

1. 00:00 Gyre 50%
2. 02:00 Gradual Pulse 30%
3. 07:30 Continuous 30%
4. 08:30 Pulse 50%
5. 13:30 Continuous 30%
6. 14:30 Gradual Pulse 50%
7. 19:30 Continuous 30%
8. 20:30 Pulse 40%

 

[fernalfer]

I don't know if this is actually the case, but it is possible that slowing down the pumps actually does more closely replicate the "real world" for fish. Aquariums are confined spaces and even if there is a lot of rock in the tank, it might be hard for fish to escape flow. Because oceans are so vast and the underwater terrain is much more complex, fish can more successfully seek out sheltered, lower flow areas during night time.

...again, I don't know if any of this is at all true. Just a hypothesis.

I very much doubt this, yes the ocean is vast but fish have territories that they like to defend and stay near they will not leave their territory into the unknown just to go find calmer water at night. they will deal with what current is going on at the time.

 

[Marcom12]

I very much doubt this, yes the ocean is vast but fish have territories that they like to defend and stay near they will not leave their territory into the unknown just to go find calmer water at night. they will deal with what current is going on at the time.

Could it be assumed they find territory that already includes an area that's calmer at any given time? Between two rocks or whatever.... And at night just go to that area?

 

[Mr.Z]

Could it be assumed they find territory that already includes an area that's calmer at any given time? Between two rocks or whatever.... And at night just go to that area?

That's what I'm thinking. A fish can stay in a very narrow area and swim out a couple feet in the open during the day and retreat back into a crevice at night.

 

[cmcoker]

Read an article on flow in Advanced Aquarist several years ago, and the author, Jake Adams, made a point that convinced me not to reduce flow at night.
"If you had to breathe (respire) as a coral breathes,this would be the equivalent of holding your lungs outside of your body, inside out, and just hoping that the wind would blow hard and long enough for you to be able to breathe. This is how corals breathe in their environment and the scenario above illustrates the importance of water flow for adequate gas exchange in corals. This perspective might make you think twice about reducing your aquarium's flow at night"

https://www.advancedaquarist.com/2006/6/aafeature2

 

[anoop 1029]

I have wondered about this topic once before. I read up about it quiet a lot too. Like all the other threads, there's always people on both sides of the fence. There's one side of how we should give our fish a break from the flow to let them rest, which is completely reasonable.

After doing my research I've come to conclusion that our tanks still need a good amount of flow at night. I find that at night when corals (if you have some) close up, this gives the tank a chance for the flow to reach detritus that the flow can't reach during the day because the expanded corals are blocking the flow. SPS at night also extend they're polyps more which I assume is to catch food in the water column.

So the choice I've made is to meet in the middle. I do maintain a good amount of random flow in my tank but turn it down by 10%-20% during the night to also let the fish rest. The fish will find sleeping areas where the flow isn't too strong for them so that they can get some sleep. The corals are still getting flow to keep them moving and not remain stagnant. Hope this fggghelps you with your decisionI agree.

I read during night we get even more waves and tides than day because of moon gravitational pull . Which makes ocean waves more aggressive than Day which confirms that it’s even higher flow rate in ocean in night than day . Fishes are evolved to survive such currents. It just that we think like humans not like fishes . Fishes doesn’t care if ocean is quite or having aggressively high current. We think as a human that we need to have calm and soothing environment while sleeping

 

[anoop 1029]

I finally have some fish in my tank (YAY!)... And wonder if I should turn off the power heads at night?.... Leaving the return pump on obviously. Or maybe turn them way down?

If you research online about tides and oceanic currents it actually higher at night than day due to moon gravitational pull .

And we think like human that we need to have soothing and calm environment while sleeping where as fish is evolved in such a high and aggressive currents , they are so use it that they don’t even care . The only thing is we should provide them ample space to hide during night as there natural instinct is to save them from nocturnal animals to get hunted while sleeping they have nothing to do with water current .
Don’t worry about them they love to be in such a high currents .
And you actually will get less fluctuations in ph during night if u keep running pump at same settings.