Question about flow at night

[kaylo]

I just finally set up my tank and I have the reefkeeper lite 3 controlling my 2x hydor 3's on a wavemaker for 20 seconds each.

When my tank goes into night mode, I have the hydor's set to turn off and the only flow going through my tank is the dual return line feeds. Is this enough flow for the tank at night?

I wanted a calming effect, but I don't know what is too calm as all this equpiment and control is new to me. There seems to be very minimal water movement at the night setting.

Thanks.

 

[JohnnyBassMan]

My opinion, we try to create our reef tanks to be like the ocean. The ocean current does not stop at night so why should our tanks current stop or slow down at night. My two Hydro’s are on 24/7 except when taking pictures from the top, so I don’t know if there is any benefit to calmer water movement at night.

Just my two cents worth. Does not mean I am correct.

 

[PogoMonogo]

my understanding is that the night mode this is mostly for the fish, to give them a break from all the flow. otherwise, the ocean doesnt slow down at night.

 

[kaylo]

I was thinking myself that without the hydor's on it just seemed WAY too calm. The racket of the hydors starting on the wavemaker timer drives me nuts, so I thought i'd try turning them off at night.

I guess i'll see what I can program in the morning so I can have them run at night but mabey not in wavemaker mode.

Thanks for your input.

 

[Aquarist007]

you want the flow to keep nitrates and phosphates and other dissolved organics to be kept suspended in the water column where they can be filtered off.

 

[pwoller]

<a href=showthread.php?s=&postid=14827965#post14827965 target=_blank>Originally posted</a> by PogoMonogo
my understanding is that the night mode this is mostly for the fish, to give them a break from all the flow. otherwise, the ocean doesnt slow down at night.

I dont mess with night mode on my vortech. All of my fish hide in the rocks at night anyways.

 

[Mike31154]

I remember a post from someone who made some night dives in a reef. He also said the ocean currents do not diminish at night time.

 

[wetWolger]

a _slight_ decrees in night currents is fine....in very high current SPS tanks I am sure your fish will thank you for it.

In the real oceans I think fish have better dead spots to relax during the night. Personally I only turn one pump off at night.

 

[sanababit]

Leave them on day and night.....

sana

 

[Anemonebuff]

I do not think the fish care either way. They get no rest in the ocean.

 

[greenbean36191]

Water flow is extremely important at night, just as it is during the day. You aren't doing the fish any favors by reducing the flow because you make it harder for them to breathe.

At night, everything alive in the tank, from algae and bacteria to fish and corals is using oxygen but there is no photosynthesis going on to produce it. The only oxygen available is what diffuses in from the surface. Even in nature (where the flow may or may not be reduced at night depending on whether local water motion is wind driven) nighttime oxygen saturation is extremely reduced on the reef, especially close to the reef structure where respiration is high and flow is reduced.

 

[Aquarist007]

<a href=showthread.php?s=&postid=14829317#post14829317 target=_blank>Originally posted</a> by greenbean36191
Water flow is extremely important at night, just as it is during the day. You aren't doing the fish any favors by reducing the flow because you make it harder for them to breathe.

At night, everything alive in the tank, from algae and bacteria to fish and corals is using oxygen but there is no photosynthesis going on to produce it. The only oxygen available is what diffuses in from the surface. Even in nature (where the flow may or may not be reduced at night depending on whether local water motion is wind driven) nighttime oxygen saturation is extremely reduced on the reef, especially close to the reef structure where respiration is high and flow is reduced.

I would assume that you have a somewhat similar answer for reefers that want to shut down their protein skimmers at night?

Another plus for running a chaeto macro refugium with reverse lighting from the daytime

 

[kaylo]

Thanks everyone for the replies.

I changed the pumps to all run day and night. I also now have my first ever refugium running opposite lighting from my DT.

 

[greenbean36191]

I would assume that you have a somewhat similar answer for reefers that want to shut down their protein skimmers at night?

No, not really. I don't think a general lack of oxygenation is a problem in most tanks, which what would be affected by running a skimmer at night or a reverse photoperiod. However, local hypoxia is a well documented and widespread problem even in the wild and the only way to really minimize it is with adequate flow.

 

[Aquarist007]

<a href=showthread.php?s=&postid=14833009#post14833009 target=_blank>Originally posted</a> by greenbean36191
No, not really. I don't think a general lack of oxygenation is a problem in most tanks, which what would be affected by running a skimmer at night or a reverse photoperiod. However, local hypoxia is a well documented and widespread problem even in the wild and the only way to really minimize it is with adequate flow.

are you saying that turning off a protein skimmer for 12 hours will not affect the level of harmful organics in the water?

Similarily turning off the sump pump/sump/refugiums/rdsb for a period of 12 hours?

(in my eg I have 4500 gph in the display tank with great surface turbulance)

The reason I ask is that in this time of trying to conserve energy my sump pump goes through a whopping 200 watts per hour.
I've cut back my photoperiod accordingly with the increased natural sunlight I have been getting in through an east facing window but have not given much thought to running the sump pump for less time for fear of rising organics ect and a less oxygen exchange that I am receiving from the skimmer, sump and two refugiums)

 

[ser_renely]

I do know the wind does typically drop in the evenings on the reef I am on. When the wind drops drops down, the ocean does shortly after. Now how much that affects the current, I am not sure, but I would think there is slightly less wave current, but it is still strong.

 

[Sisterlimonpot]

you also have to think about the gravitational pull of the moon at night

 

[kaylo]

I remember going fishing at the coast at night in a new moon and it seemed like there was no movement with the waves at all. It was kinda erie and we were catching some stuff you normally wouldn't off the shore.

I think this is where my assumption of alot less movement at night stems from. But then again, our tanks are somewhat different than the ocean by comparison.

 

[supercharger]

interesting

 

[dancewithethan]

Having spend a lot of time on and off the tropical ocean, the ocean surface and waves are a lot calmer at night. Now, I do not suggest that we don't need wave in our tank at night. personally, I don't have as much water movement in my tank at night because of the above reason. I figured, if nature has been doing it for millions of years than why change? Now, this is my opinion and I know the majorities here prefer to run full blast 24/7 and I don't have problem with that either.