Mimicking Tidal Flowing Our Reef Tanks

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As more and more discussion is happening with creating a better environment for getting corals to spawn in captivity (or just better coral health in general), some of this discussion revolves around water flow; especially ramping the flow up and down in relation to the lunar cycle.
I've had this idea floating around since 2014 when I brought it up on another forum. I want to bring it over here so we wouldn't have to go over there. And more selfishly, I am still interested in this topic and would like it to see more attention; and possibly a solution.

Here's the copied/pasted posts from my original thread.

Originally Posted by jlanger

I would like to open up some discussion on trying to mimic the water flow found on the reef in our own aquariums.
This has been on my mind for a while, but I thought I would open it up to the masses for more insight and ideas.


Ever since EcoTech Marine updated their ReefLink to work with their VorTech water pumps, I have wanted to try and create a program to create a more realistic representation of what the water flow is actually like on the reefs.
EcoTech Marine has done their research and have created a couple of modes to simulate what flow is like on the reefs.
I have been doing quite a bit of reading and researching of what actually happens during the cycles of water flow on the reefs.
Having owned and used the VorTech pumps for four years, I have tried various modes and settings. These pumps do create a very nice random flow in my tank; I'm not complaining. But I still have not found what I am looking for.
I think with this discussion and further research, we can find what I am trying to achieve with my water flow.
And in all actuality, there may be no beneficial effect from all of this; just like running static moon lights every night.

Equipment and Methodology:

I currently use four VorTech water pumps on my 120gal; two MP40's and 2 MP10's. Each MP40 is paired with an MP10 which are located on opposite side of the tank. The pairs are run anti-synched; so the MP40 on the right is synch with the MP10 on the left and vice versa.
I primarily run the pumps using the EcoSmart Tidal Swell Mode. The night before I do water changes, I switch to the EcoSmart Nutrient Transport Mode.

Here's EcoTech's specifications about these two modes.

With the EcoSmart Tidal Swell Mode, the flow pattern will shift from an emphasis on chaotic left-to-right flow direction into a right-to-left flow direction, with periods of calm in between – followed by a great surge of flow at the very end of the cycle.


With the EcoSmart Nutrient Transport Mode, water is circulated in two phases – a wave motion to stir up detritus, and a surging motion to move the detritus into your overflow.


Long ago, I asked EcoTech Marine how long the cycles were for each mode.
Each mode cycles in 2-½ hours; the pulses in the NTM are for 45 minutes and the swelling is for 30 minutes each.

So as I have dabbled with the EcoSmart Live program, I was trying to find a way to create the "perfect" program to mimic the water flow on the reef.
I know many people like to ramp down the flow during the overnight hours. And some people even run all through all options during the course of the day.
To find the program I wanted, I knew I had to do more research.

Research and Findings:

I started my research with books that I already owned; Delbeek and Sprung's "The Reef Aquarium" series and "The Encyclopedia of Modern Coral Reefs". I moved on to various reefing webpages on water flow in reef tanks. On a whim, I expanded my search outside of the aquarium hobby and I stumbled on to a couple of books/papers discussing tidal swells. It wasn't until I started reading about tidal ebb and flood that I knew I found what I was looking for.
This hobby has spent a lot of effort discussing (and selling) the importance of the lunar cycle in respect to lighting, but not enough on the effect of water flow.
I should have figured this out earlier.
When I was running the Vertex Illumina LED fixture over my reef system, it had a lunar cycle for the moonlighting that would ramp up/down in conjunction with the actual lunar cycle.

One book was worth looking into is "The Dynamics of Coastal Models"; particularly the Effect of Changing Water Level on Flow Over Reefs.

In a paper directed at bodysurfing, "Ebb and Flood: The Science of Tides" discusses and details the changing flow of our ocean's water during the lunar cycle. The paper exhibited a couple of interesting graphs that more than reinforced that this was what I was trying to figure out for my tank.

This graph shows the tidal differences during the course of each day over one month.


And this graph shows various tides and their respective levels during a 24 hour period.


Based from these last two resources, I am trying to figure out how I can create a program for my water pumps to mimic these findings.
Using the modes that are available with the VorTechs, there must be a way to create the variable flow of a true tidal ebb and flood within the aquarium.


To achieve a more true tidal swell, I feel that the two EcoSmart Modes need to be combined somehow into one program.

I like the effect from the Tidal Swell Mode of changing the direction of the flow from one side to the other.
But I do not like that the cycle only lasts 2-½ hours and that both pumps run simultaneously.

I like the effect from the EcoSmart Nutrient Transport Mode that creates short bursts of flow that ramp up over time.
But I do not like that the anti-synched pump immediately pushes back against that flow.

The ideal program should create a semidiurnal tide (two high tides and two low tides) in a 24 hour period.

My Ideas and Thoughts:

To keep the effect of water surge, the pumps should run in a pulse mode; maintaining the "lovely" swaying motion of the coral's polyps.

When creating the ebb or flood, only run one pair of pumps at a time. Maybe running both pairs just during the peaks and valleys of high/low tide could create more random flow during the changing of the tide.

As the tides change, the ramping up and down of the pump's flow and pulses increase and decrease with the tide.
In looking at the final graph, when the graphed line is at it's steepest, the flow and pulse would be at it's greatest. When the line starts to level out, the flow and pulse are weaker.

If I had the time, I could create a graphic depicting the above ideas to better clarify my thoughts. Maybe later.
Think of it as almost like combining the two EcoTech graphs into one; pulses that ramp up and down over time against each other.

But I'm still struggling on how to create the more dramatic changes with the lunar cycle; as shown in the "January 2014" graph.
The water flow and pulses would be more dramatic during the new and full moon cycles, and more stable during the half moon phases.

The EcoSmart Live, as far as I now, only works on a daily cycle; not a monthly cycle.
I'm not sure if I had the pumps controlled through a secondary controller, like an Apex, that I might be able to create a monthly cycle.


So after reading through all of this…
Does anyone have any additional thoughts about trying to create a tidal/lunar cycle with the VorTech water pumps?

As I wrote all of this out, many things fell into place for me concerning what I was looking for.
It's just trying to figure out the specific and getting it to work that is still open for discussion.
As like I stated earlier, none of this may have any effect on such a small system.

Thanks for reading.
Thanks for any input.

And this was my second response trying to visual explain my thoughts for a EcoSmart program mimicking tidal flow.

Originally Posted by jlanger

Anyways, here's a quick illustration trying to explain my late night ramblings.

VorTech Lunar graph.jpg

So over a 24 hour period, there will be two cycles by each pair of pumps.
It is hard to tell in this smaller graphic but as the pulses get stronger, they also get longer.
Overlapping the two pumps for a brief time will create the random flow of whirlpools and eddies created during the tidal switch.

So the trick to simulate the lunar cycle would be to change the Max% of the pumps over 28 days.
During the full/new moon phase, the Max% would be greatest; say 80%
And during the half moon phases, the Max% would only be about 40%.

In my illustration above, the orange and blue graphs depict the power and duration of the Vortech pump. The Blue line graph depicts the time and height of the daily tide.
As the tide rushes in/out, I feel the Vortech pumps would run at the set maximum setting for that day. When the tides reach high/low tide, the pumps run at their lowest setting as the water flow begins to transition the other direction.

I have recently synched my Vortech pumps with my Apex WXM Module and Controller, so I may try to figure out a way to achieve something similar to this using the already existing EcoSmart Modes.
I am trying to think if there is a way to use the Seasonal Modes to incorporate the rising/falling maximum settings that correlate with the lunar cycle.

If Ecotech Marine would like to take this into consideration for a new EcoSmart Mode, I would be glad to assist in any way needed.

Thanks for reading through all of this.
And any additional thoughts would be greatly appreciated.

That was the original post.
I will add some of the replies and added content that I found interesting to further the discussion here.
Great post. I'm working on some special covers for my mp40s in hopes that I can add a 2nd pump and try to turn a more natural flow on my tank rather than the cat and slow toilet bowl flow. This post was just in time.

I don't have anything to add at the moment but thanks for sharing.


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More content....

I've done some looking around at other people's advanced programs for their pumps, and I have a newbie's grasp of the basic language.
I have a couple of theories as to how to start getting close. My problem lies on the lack of modern programming expertise; my proficiency stopped circa 1990.
I found this program on R2R with quite a bit of programming options. I know that that posting is a few years old, but it's a start.

The [first] question I have is where in the Apex Dashboard do you set up the custom modes that are listed at the end; i.e. P100, N100, VOFF,....
And a secondary question, what do the (PF##) stand for and do?

I believe that I will need to create multiple custom modes using the Pulse Mode at various percentages (i.e. 10%, 15%, 20%, ...) to create the rising/falling speed of the pump to create the singular tidal flow arc over a seven hour time period.
And I would create these custom modes to reach the maximum values during the new moon and full moon.
Once a single tidal flow arc is created, I can repeat the program five hours later. And then I can set up the slave pump to run opposite the master pump.
Running a seven hour ramping cycle would allow a half an hour of both pumps running together every six hours to create the random flow of the switch in tidal direction.
*** As of now, I am fine with not trying to program a shorter-longer pulse within the single arc.

Now that a single day of programming is outlined, it's time to create the 14 day half-lunar cycle.
Is there a way to program a looping cycle based on the number of days in the cycle?
So program starts with a day value equalling zero and each 24 hour period adds one to the day value. When the day value equals 14, the program resets to a day value of zero.
With the pumps being initially programmed with the maximum speed limits during the new moon and full moon, is there a way to make each day value a percentage of the maximum speed limit?
So as the days pass from Day 1 to Day 7, the custom mode runs at a falling percentage of the daily program. And as the days pass from Day 8 to Day 14, the custom mode runs at a rising percentage of the daily program.

So back to my limited programming knowledge... I'm trying to figure out if you can run a program (daily cycle) within a program (14 day cycle) using the Apex Controller.
And I will be needing to set up two programs, one for each pump; master pump and slave pump. The same program just offset by six hours.

I know there's plenty to think about and hopefully you can decipher what I'm trying to explain in writing.
I'm excited to see what I(we) can come up with for a Tidal Flow Program for our reef tanks.

Any and all help, thoughts and discussion is greatly appreciated.



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Some added excerpts...

tigé21v said:
A couple of questions..
Would you need the short pulses in the alternating tides? I thought the tide itself was pretty much similar to a river coming/going- a continuous flow (that does increase/decrease relative to time), with the random flow coming from wave action, which is caused by the winds flowing onto shore.

jlanger said:
My thoughts of using the short pulses was keep the random motion of the wave that we see with polyps moving back and forth along with keeping the direction of the tidal flow still coming from one direction.
Yes, the tidal surge is coming/going in a continuous flow from one direction, but during this time there is random flow created by the reef itself. When the water in the tidal flow hits the reef, that water will flow stop going in that direction and be forced back into the flow causing areas of random flow. When the pulse is off, this allows that flow to "relax" for a short time and this would provide relief to the corals from a constant surge in one direction. This is what most people are trying to re-create when the set up the back and forth motion with wave makers and the like.
With my theory, as the pulses get longer and stronger, more and more water is being pushed in the one direction during that phase of the tidal surge. And as those pulses are getting longer, the "off pulse" remains constant (short) so that essentially the column of water is being pushed in one direction during that phase.
I hope that helps explain the thoughts of using pulses.

jlanger said:
From the start, I stated that all of this discussion may not make a difference in a home aquarium.
But I also feel that there should be some benefits to incorporating tidal surge as water flow.

If we remove the discussion about trying to create a daily cycle of high tides and low tides, wouldn't the effect of the monthly cycle of the lunar phases still account for further discussion?
Just about every reef lighting manufacturer has incorporated lunar lights and programs into their fixtures. And there have been discussions about how replicating the lunar cycle has benefitted corals in captivity with regards to spawning events. Whether this occurrence is substantiated with the lighting cycles or still gravitational pull from the real moon itself can be debated.
But if lunar lighting cycles are having a positive effect, shouldn't we still try to create a tidal surge based on the effects of the lunar cycle?

As the lunar phases change, the tides themselves change.


The graph above shows that during the new/full moon phases, the tides reach their highest point. During these phases, the water flow inside our tanks would be stronger and more turbulent.
So, is this where we should concentrate our efforts on mimicking the tidal surge in our tanks? Lunar surge, not tidal surge?

jlanger, you could use multiple "If Sun" or "If Moon" Apex programming statements in the Advanced programming area for each pump and tie them to the rise/set times in the Season Table built into Apex. These are used for lighting but could be used for pumps as well. You create profiles of what you want your VorTechs to do at interval times set by the Season table which would be changing throughout the year. The Season Table is also editable so you could configure rise/set times to match your location.
Have a look at these two threads may be helpful to get you started:
Review My Program: jeabo wp40 program
Neptune Apex Seasonal Lighting Table for EcoTech XR Series

Robbie Gibbins said:
I may have missed it. But there is usually about an hour of slack tide with little to no flow at all. Incoming tide, Slack for an hour then Outgoing

jlanger said:
What I chose to do in my original proposed graphs (below) was to have the master and slave pumps both running at very low speeds during the switch in the tidal direction.
I didn't want to have any period of time where there was no pumps running, so I had the two programs slowly work together to achieve some very low random flow before the switch was made.

VorTech Lunar graph.jpg

If you really wanted a slack tide, the programs could easily be shortened to allow for a period of time with no pumps running.
Thanks for the input.

As a side note, I have been running the same program since I posted in May and I like it; it's not exactly what I'm looking for with this thread, but it's a decent back-and-forth wave.
The corals that are growing are showing nice forms.
And you have to wonder if the fish are affected somehow. My Scribbled Rabbitfish likes to bob with the wave at the top of the tank at night and my Lyretail Anthias have begun to spawn regularly since July.

stevieduk said:
Point two ,, If you dive on the edge of a drop off on a coral reef, were the good corals are, you will find that the current runs the same way for 6 ish hrs , then there is a hr of slack water, then it reverses for another 6 hours , as in most seas in the world.

jlanger said:
Your second point describes what I had tried to illustrate in my "Vortech" graph above.

If you consider the rising of the tide as the master (blue) pump and the the falling of the tide as the slave (orange) pump, you see that the flow of water is coming from one side of the reef for five hours with an hour of overlap (combined flow/slack tide). The only time that both the master and slave pumps run together is during that hour that the tide switches direction.
Where I think some people are getting it wrong is that the slave pump doesn't run in the traditional method that the Ecotech programs run them. My "slave" program is the exact same program as the master program but it is offset by the six hours or so.

I chose to use the pulse mode over a continuous speed mode bases on the small footprint of our aquariums. (I know that my corals do not appreciate a continuous blast of water.) And it may be hard to see in the small graph, but I did describe how the pulses get longer and closer together as the speed of the pump reaches it's maximum; hence an almost constant speed setting.


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jlanger said:
I have not achieved a monthly surge program, although I do have the Vortech pumps set up to mimic the rise/fall of the tides.
The four pumps are set up as two pairs; front right with rear left, front left with rear right.
The pumps alternate a three hour full speed cycle nested between a three hour shift.

For months, I had been running multiple modes on the pumps that created a very nice pulsing wave throughout most of the day. When I sat down and calculated the exact amount of flow that the four pumps were creating, I found it to be very low. When pumps are set up in pulse modes, they're constantly cycling on/off which cuts the flow drastically. From doing some research and experimenting, I found decided that the best utilization of the pumps is to run them on the constant mode. The pump is always moving the amount of water that you set as the maximum speed. And from listening to Austin's talk at MACNA where he states that the corals need an incredible amount of flow, I turned up the maximum speed to 100%; contradictory to my previous thoughts. By allowing the slave pumps to remain at a minimum of 25% of maximum speed, random flow is still being created; it just shifts as the cycles change.


I should add that I am not currently running my four Vortech MP40 pumps with this program. I've been very lazy and they are all just running the Reef Crest Mode since I rebooted the system a few years ago.


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@jlanger Jason, I've been following the discussion on the ReefBeef discord channel, nice to see your thoughts and previous work discussed more fully and some of the resources you are drawing from. Unfortunately, I don't have enough experience with controller programming to be of any help, but I'm following along as I'd like to do some coral spawning in my classroom at some point, once I have enough experience and the proper equipment to do so.


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I was trying this a while back although not tied to real world cadence. I run redundant return pumps both of which are Neptune Cor's. One is a 20 that has the longer plumbing run and also feeds refugium and one 15 that feeds the shorter line. Each return fed a 1" sea swirl on opposite sides of the display so "in theory" this would give me a slow alternating left, right, look and feel. Worked ok but where they intersect at around 40% my sump level would change. I never took to work on the ATO programming to disable it during this time frame :(

Second attempt I left them at normal power but used a virtual output. A hard switch on/off using the OSC command which is a repeating On/Off interval. I think it stands for oscillation. Anyway you specify the number of minutes and seconds to be on then the number of minutes and seconds to be off. In my case I'm telling it to run for 360 minutes which is 6 hours to alternate between on/off. This worked better and I did not have sump level issues. I had to change one of the pumps placement so ended up turning this feature off although I may pick this back up although I am in the process of switching out return pumps.

Although new display I will revisit using a closed loop I think.

Virtual outlet:
OSC 000:00/360:00/360:00 Then ON

Cor 15 return pump (advanced view):
Fallback ON
Set 80
If Output TideTiming = ON then 20

Cor 20 return pump (advanced view):
Fallback Off
Set 35
If Output TideTiming = on then 80

First attempt - alternating flow schedule:


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I forgot to mention that when I was playing around with this I was starting to get frustrated with my display which is another reason that I stopped. This is just my opinion but I feel that a displays design has to have this in mind before it will work properly. Over flow type, location, and number of return lines to include location all play a roll. Direction and collision all seem to effect what the power heads or return lines do.

I do not know how the power head graphs and patterns are generated but I'd wager in a static environment without competing forces or aquascape/coral growth and maturity.