Do you cut down on flow at night?

[LosingSleep]

Does anybody else cut the flow down at night? During the day I'm turning the tank over about 26x an hour using alternating/"wave" making system. With all powerheads on, it would turn the tank over 35x. At night I figure the fish would like a break and I cut the maxi's which brings the flow down to 17x an hour. Should I go less or leave it cranking at full tilt?

 

[Yaktop]

the ocean normally calms at night so yes........

 

[JayM]

I shut down 1 of my 2 tunzes at night on my 92.....it's on the same timer as the lights

 

[MartyM]

I think the same reasons you have a lot of flow during the day still apply at night. For example you still need to keep detritus suspended so it can get to your skimmer and the corals still need good water movement to supply nutrients and remove waste.
Keep in mind that on a reef the waves generated by the daytime winds might die down at night, but the tides and currents are still going strong.

 

[~Flighty~]

the ocean normally calms at night so yes........

I always hear that, but I've never quite bought it.

Night dives I've done on the reef were the same current conditions as the day ones. I've been on sailboats in storms at night.

Is it maybe an illusion because there are fewer boats making large wakes near shore at night so the waves sound quieter?

Tides going up and down making current aren't day/night dependant.

Offshore onshore wind changing with the heating and cooling of the land from the sun is a day/night thing, but I don't think that means all or even most reefs have less water movement at night.

It is an interesting question, I'd love to see evidence either way.

 

[vass]

I may be mistaken but if anyone has Eric Boremans book there is a section where he states the some corals benefit by having increased flow at night. I,ll look for the quote tonight and post it.

 

[TomD]

Shouldn't there be more O2 at night in a closed system because photosynthic animals respire.

 

[~Flighty~]

I think that's backwards. The O2 is released during daylight as a result of the photosynthesis going on.

 

[Dave McReeferson]

Nope, flow stays the same day and night in our tank.

 

[TomD]

I think that's backwards. The O2 is released during daylight as a result of the photosynthesis going on.

Right! I just said it wrong. I meant they do not release O2 at night so why would cutting the flow be a good idea?

 

[LockeOak]

In my 10G I have a MJ600 that is on for 7 one-hour periods every 24 hours, due to the spacing I think there might be 4 at night, 3 in the day. Roughly equal.

 

[RichConley]

Waves calm down at night. Tidal currents, and such do not. Most of the flow that most corals get isnt from waves.

 

[Rays]

Waves calm down at night. Tidal currents, and such do not. Most of the flow that most corals get isnt from waves.

Yup