sps and flow

[spit.fire]

I aim for 45x turnover 24/7

[MitchM]

For a proper SPS environment, aim for alternating flow> 20cm/second.
See this article.
http://www.coralscience.org/main/art...ow-corals-feed

and articles like the one in this PDF.
www.int-res.com/articles/meps/212/m212p301.pdf

Slowing it down at night for the sake of the fish isn't a bad idea.

[Aquattro]

Here's my setup which seems to serve me well. Ya, it's long...

I run this on two sets of Tunzes. I then have a WP60 on random and adding a second this weekend.

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Wave1 (This is my main daylight wave pattern)

Synchronize Enabled
Divide by 10 Enabled
Initial off time (Seconds) 0
On time (Seconds) 7
Off time (Seconds) 4
Minimum intensity 0
Maximum intensity 100

Wave2 (Similar pattern to the above but Syn is disabled which creates a bit more chaos)

Synchronize Disabled
Divide by 10 Enabled
Initial off time (Seconds) 0
On time (Seconds) 7
Off time (Seconds) 4
Minimum intensity 0
Maximum intensity 100

Lt_Flush (This is for the left side 6205 flush)

Synchronize Disabled
Divide by 10 Disabled
Initial off time (Seconds) 0
On time (Seconds) 30
Off time (Seconds) 30
Minimum intensity 0
Maximum intensity 90


Rt_Flush (Rt 6205 alternate interval of LT_Flush alternates one on while the other is off)

Synchronize Disabled
Divide by 10 Disabled
Initial off time (Seconds) 30
On time (Seconds) 30
Off time (Seconds) 30
Minimum intensity 0
Maximum intensity 90

DuskDawn (This is a lower flow wave pattern used intermittantly during the light hours as well as before and after lights go out)
Synchronize Enabled
Divide by 10 Enabled
Initial off time (Seconds) 0
On time (Seconds) 7
Off time (Seconds) 4
Minimum intensity 0
Maximum intensity 30

Night (Sets a constant 30% flow during light off hours)
Synchronize Disabled
Divide by 10 Disabled
Initial off time (Seconds) 0
On time (Seconds) 10
Off time (Seconds) 15
Minimum intensity 30
Maximum intensity 30

I am up to 3 timers. My use for the timers is to create short random periods of different flow during daylight hours.

Timer1 (turns on every 120 minutes for 10 minutes. If timer 2 is on at that time, it should remain off.

OSC 120:00/010:00/000:00 Then ON
If Outlet Timer2 = ON Then OFF
If Time 19:30 to 11:30 Then OFF
If FeedA 000 Then OFF

Timer2 (turns on every 45 minutes for 15 minutes except if timer 3 is on)
OSC 045:00/015:00/000:00 Then ON
If Outlet Timer3 = ON Then OFF
If Time 19:30 to 11:30 Then OFF
If FeedA 000 Then OFF

Timer3 (turn on every 15 minutes for 5 minutes except if timer 1 is on)
OSC 015:00/005:00/000:00 Then ON
If Outlet Timer1 = ON Then OFF
If Time 19:30 to 11:30 Then OFF
If FeedA 000 Then OFF


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These are the variable speed pumps and their programming:
StreamLt
Set Wave1
If Time 10:30 to 11:59 Then duskdawn
If Time 12:00 to 19:00 Then Wave1
If Time 19:01 to 20:00 Then duskdawn
If Time 20:01 to 10:29 Then Night
If Outlet Timer1 = ON Then Lt_Flush
If Outlet Timer2 = ON Then duskdawn
If Outlet Timer3 = ON Then Wave2
If FeedA 000 Then OFF


StreamRt
Set Wave1
If Time 10:30 to 11:59 Then duskdawn
If Time 12:00 to 19:00 Then Wave1
If Time 19:01 to 20:00 Then duskdawn
If Time 20:01 to 10:29 Then Night
If Outlet Timer1 = ON Then Rt_Flush
If Outlet Timer2 = ON Then duskdawn
If Outlet Timer3 = ON Then Wave2
If FeedA 000 Then OFF

[KPG007]

I have one tank (well, 2 now) that I dial the wave action down at night, and even turn off one of the lower pumps to, as Brad said, give the fish a chance to sleep a little more peacefully.
In another tank, there is no flow reduction at all, just a lot of holes and calmer water behind the rock work for the fish to sleep.
In all cases the coral is healthy and happy and growing well. So I do not believe flow duration plays much of a part in coral health.