SPS and reduced night time flow

[dan223]

Has anyone observed benefits from slowing down flow at night hours during lights out? I can see why people may think it could help with prey capture/feeding, but on the other hand that is when the corals are growing and could need full flow for exchange of gases or nutrients. Have any of you observed increased growth? Does more PE really mean more growth or healthier?

 

[Muddy35]

Dunno bout corals but the fish seem healthier. As far as growth on corals? I have a red planet that puts on about 1/4" a week but that could be from a large number of things.

 

[klepto]

Has anyone observed benefits from slowing down flow at night hours during lights out?

Think about corals sitting on a fringe reef. Do the waves and currents suddenly drop when the sun sets? I think it is a good idea to maintain normal flow at night, especially if you are keeping SPS. Oxygen levels are already going to be lower at night, and further reduction should be avoided. As you mentioned, keeping flow up will help with nutrient and gas exchange.

 

[dan223]

Think about corals sitting on a fringe reef. Do the waves and currents suddenly drop when the sun sets?

Well actually winds usually pickup during the day and die down at night, atleast inland. The limited time Ive spent near the ocean I thought I noticed the same trend, or do the waves usually stay the same night day?
Anyway rather than speculate I thought I would see what people have observed in their aquariums.

 

[uireef]

I run a tunze stream system and a wave box that has the night mode using a photo cell. So at night the wave box stops running and the pumps flow lowers giving a more calm currrent. I think lower flow helps at night by letting your corals grab food and not get blown away. During light period its crazy flow in my tank, that's how to keep large colanys happy.

 

[DarkXerox]

I have night mode activated in my vortechs mainly for the fish since they get spooked when the lights go out. It definitely helps the LPS in my tank capture food when I do my night feeds, but the SPS don't seem to be suffering. The vortechs drop to about 50% power and exit nutrient transport mode which calms things down for sure. I'm not worried about the pO2 dropping either since the return pump stays at full as does the skimmer (plus a reverse cycle refugium).

 

[chercm]

i never slow down the wave at night , same wave during the day

 

[klepto]

Anyway rather than speculate I thought I would see what people have observed in their aquariums.

Fair enough, I was just offering my thoughts. I have never noticed a pattern where the waves suddenly dissipating after sundown, but that is just my experience. Sorry if that is overly speculative.

 

[uireef]

i never slow down the wave at night , same wave during the day

Why not?

 

[chilwil84]

i dont know about the pacific but during any of my trips to the caribbean the best time to snorkle the shallow reefs is always first thing in the morning because as the day goes on the sediment in the water always goes up thus the visibility goes down, so i would guess there would be less flow at night and more during the day.

i also live on the jersey shore and the ocean is calmer at night here.

 

[Maivortex]

In Hawaii the ocean calms down at night

 

[buy_baff]

You will get way better polyp extention if you slow the flow down at night, I use the night mode with my mp40s.

 

[-=Efrain=-]

You have to consider what creates waves and that is wind and wind direction. So with that being said wind gets created in most part by thermos (hot air hitting cooler air) and when the sun sets the thermos are reduced and therefore waves are reduced for the most part.. So yes waves are less powerful when the sun sets in most situations. Also waves do get bigger as water goes from deeper water to shallow water like when they hit reefs but it all goes back to thermos creating the wind in the first place which means the sun.. Turn off the sun and you get less thermos and less wind and smaller waves..

 

[dan223]

:lol2: good good I thought maybe I was crazy for a minute. Yes the warming of the sun, thermal gradients etc. etc. Again though rather than hypothesize about the ocean and what may or may not be happening in nature, Im looking for feedback from people who ran a thriving reef for a good amount of time with the same strong flow 24/7 and then went to a nighttime slowdown and noticed change. It seems alot of the time that the best evidence we have is observations.

 

[smokenax]

everything in my tank likes calmer water at night specialy chalices.

 

[Justin74]

Excellent topic, thanks for posting this! I've always heard the same speculations, but I too have subscribed to klepto's philosophy for most of my reefing experience, no science to back it up, just a feeling. I get extreme amounts of PE with my tunze's left on at night though, so I dont fit into a standard category I guess. I've dismissed others claims regarding lack of PE for what I thought were apparent reasons. If the food is being blasted at it through high current, does it really need to extend to reach out and grab it? To do so would be just a needless waste of energy. Same thing with people who witness low PE and body expansion on soft or lps corals that have overly intense lighting. The need to expand is lessened because it doesnt have to pan out for the light, the light is coming to it in full force..again more speculation for the pot..

Think the size of the tank and/or how pH is being maintained is crucial in trying to comprehend the totality of this subject and what may be others success or failures at it. Since I have a smaller system it fluctuates a lot faster, so turning the powerheads off is just a risk Im not comfortable taking for stability's sake. Think this would be more successful in larger tanks though, definitely no nano talk here...

Again, great topic!

-Justin