Are the seas really calmer at night?
 

I've looked at the photocell attachments for the tunzes and on JL's website it states:
I was not aware that mother nature have been so considerate to the animals that inhibit the ocean. However I do not have any personal experience in this field so my question is: are seas actually calmer at night vs during the day? Hmmmmmm :question:

Chin, I haven't been swimming in the ocean at night, but I know for the cost of this attachment, I'm happy with it. :biggrin:

I am the other side.

I purchased one and am not happy with the results. I found that with the reduced current at night my corals started bleaching. This was found in some of my nicer acro's.

SO i took the photo cell off. If someone want's it than it's there's for $5 :biggrin:

Jon, any hypothesis on this bleaching? I can't see why that would affect the corals one way or the other.

It was mostly in my tri color acro that was in the highest flow area in my tank. I added the photo cell to drop my controlled tunze to 1300gph at night. About 2 days after adding it I noticed a decline in the coral.

I did not realize that the photo cell addition could have caused it till i looked back in my journal and did some reading.

Re: Are the seas really calmer at night?
 

I never really thougt about it before,but come to think of it it does seem that way.I can't really remember a stormy night.And I spent quite a few of them out to sea.

yes they are and it is eerie. having been to many tropical coastal cities I can tell you the wave action calms down at night (unless it is storming) and the water becomes calm. I have even noticed this while I am sailing in the middle of nowhere. now this is just surface action, the tides are still moving and the currents don't slow down so do we in our tanks need a photo cell to calm it down at night. Not in my opinion as I am not trying to recreate the wave area on the beach.

Steve

This question was also a topic on Reef Central over the past month, and directed to Anthony Calfo for a response. Here's the link below:

http://reefcentral.com/forums/showth...hreadid=497826

Bottom line, Calfo is not a fan ...

Interesting point was brought up in that RC thread. Even though there is constant flow in the reefs, it goes 11-12 hours in one direction, then 11-12 hours in the other direction. Maybe I should try putting powerheads on each corner and put them on alternate 12 hour cycles.

actually its only 5 or 6 hours at a time, 2 tides per day. but it doesn't matter much as that isn't the water current we should be trying to recreate as that is just coastal areas and channels that are affected. Most of the reefs are on the edge of currents where the direction doesn't change at all.

Steve

Change...
 

Jonathan
maybe its just the change that caused the decline. IME, when there's a sudden change of something it usually caused a slight decline in my corals but after a few days, they adapt and continues to thrive. How long was the tri-color positioned at the highest flow area before the change? Did it completely bleach or did it come back after awhile?

I wonder though. How much is that effect due to the fact that winds (unless it's stormy) tend to die down as soon as the sun sets? The waves gets churned up by winds, but convection currents etc. basically dwindle as soon as there's no sun heating up the earth's surface.

I have no idea what is happening to the currents under the surface, as I have never done any night dives. But tides and so on keep going obviously.

Re: Change...
 

The tri color colony has been in the high current area for the past 13 months. The colony was about the size of a soft ball. I have heard that larger coral colony's don't like sudden change so I can only assume that it didn't like the decline in current and did not recover.

I broke the tips off as the base of the coral was receding over a 4 day period. The tips have been reglued onto another rock and the coral is still alive but white. I can just see some light green in the polyps again. So hopefully it is comming back as it was one of my most favourite acros I have.

:eek: Wow, that is sensitive. I guess my frag's not moving.

Just last week while I was waiting for my new upgrades of the Seio 1500 to arrive, I was down to about 1000g/hr of circulation from 2500g/hr. In the middle of the night I noticed the polyp extension on the Acros has been longer than any other time before. It normally extends considerably at night, but on these two days, it was double or triple it's length.This leads me to believe that low current does benefit the corals feeding habbits in some way....good I hope. I may have to do futher testing to see what the long term affects are. No signs of decline or bleaching on any of the corals previously in high flow areas.