Simulating The Reef, Temp swings and all

[cocojakes]

So I recently got my tax return, and then quickly spent it all on a pair of Kessil A160WE and an Apex. (for those of you that know my constant struggle with enjoying my lighting, I absolutely love the Kessils. My only wish is that they dimmed a bit more in the low range. they seem to go from 15% to Off) but anyway, thats not what this topic is about.

 

Even more recently, I found this great website, that has live data from different points on the great barrier reef. more specifically, PAR, air temperature, and water temperature (6m below the surface).

 

http://data.aims.gov.au/aimsrtds/station.xhtml?station=1&time=last12hrs&level=0

 

I took the data from one of these stations, for the past week, and averaged it out, and graphed it, and for anyone interested, this is a standard day (this past week) at Agincourt Reef station #3 from 2am till 2am

 

 

I found a few things very interesting, the more obvious observation was that on the reef, the lights don't "turn on" then at dusk "turn off". Theres a ramp time, but what I guess i kinda knew, but didn't ever take into account, is that theres no real plateau at the top. My LEDs ramp up for 2h, and ramp down for 2h, but they sit at full for 6h in the middle, which is not at all what happens with the sun, its a parabolic wave of light. So thats the first thing I changed. I now have five ramp profiles for my light intensity. A steep 2h rise from 0-60%, then a 1h rise from 60-80% then 3h from 80-100%, then back down, 2h from 100-70% and 3h from 70-0%

 

The next thing that caught me off guard was the temperature swing. Remember this is an average of the week. Over the whole week, the swing was about 27.7C - 28C (81.8F - 82.4F), but thats an average, there were some days where there was closer to a 5F temperature difference from peak to vally, and other days where the temperature almost stayed perfectly flat (I'm going to assume based on ambient weather, clear sunny day vs cloudy and overcast, or perhaps rainy). The most startling thing for me, was that the peak temper, especially on the hotter days, was after sunset.

 

So, I went to work trying to change my temperature settings. I now have 5 temperature levels, 78,78.5,79,79.5,80. Which I try to group around the rise and fall times compared to my lighting schedule (Dawn for my tank is 11am, dusk 10pm). The overall point behind this thread, other than getting out this amazingly cool information to people, is basically an apex question. I know I can make ramp profiles, but can I use the current level of the ramp profile, as an input for an argument to turn on or off a heater?

 

Basicly can I have a ramp that goes from 78-80 over the course of 7h, and a ramp that goes from 80-78 over the course of 17h, and then have the heater turn on when the temperature is lower than 0.1 degree below the current ramp level, and off when 0.1 degree above. Basicly I want to minimize the stair stepping effect I get by changing temperature 0.5 degrees at a time, without having to make 20 virtual outlets lol

 

 

Also, I'd love to hear peoples input on the information I found, and how I'm using it

[amphipod]

Matching nature better, your corals might grow better

Water has high specific heat capacity, basically cools slow heats slow explains delayed warming

[seabass]

In the ocean, the temp can't climb and fall 0.5° as quickly as it can in a home aquarium. I'd make 0.1° changes instead. I feel that temp changes help determine spawning cycles in many species (along with other seasonal changes, like duration of the light cycle and even the phase of the moon). In order to mimic nature, you might try to make seasonal adjustments too.

 

For lighting, some people use moving fixtures which simulate the rise and fall of the sun (as the sun doesn't just sit right above the reef and change intensity and spectrum). Nowadays, there are some light controllers that mimic clouds, and even lightning.

 

It's interesting to try to simulate nature, but there are many variables that are difficult to recreate (like the availability of plankton, stability, diversity of life/food, ect). If you have the time and resources, simulating nature more closely is a worthwhile endeavor. However, it is not typically required to keep most common species alive and growing.

[cocojakes]

I would love to make 0.1 degree changes, but that means I need 20 virtual outlets, and I'd really rather not be programming 20 virtual outlets just for the heater. Thats why I'm looking for a better way of controlling a slow change with the apex