|
|
|
Group: Forum Members
Last Login: 2 days ago @ 3:12:13 AM
Posts: 374,
Visits: 1,803
|
|
The only argument I have made and I think is valid (others also mention this) is that reef corals often live near their upper thermal limit and by running tanks warmer, there is less of a safety margin.
Yeah, but the thermal limit changes with the ambient temp, even on a seasonal scale. I really doubt keeping the tank on the cooler side actually provides any more wiggle room. The people reporting problems at 82 or so suggests that it doesn't. I use BTAs that come from a reef that sees summer maximums around 78 so I only have to crank the temp up to about 82 to do stress tests. People have done the same with Pocillopora from the same reef. Meanwhile the same species in my personal tanks would rarely see summer temps below 82 without issue.
The best explanation I've seen for keeping temps cooler is that its just a holdover from the days when livestock from FL and the Caribbean dominated the hobby, so the upper 70s was closer to the natural temps where the animals were coming from. 78 was already established as the "ideal" temp by the time the majority of stuff started coming from the Pacific, so it was hard to convince people to change, especially when their books said 78 was great. It also doesn't help that the reefs that are closest to most forum users are also some of the coldest ones (FL, Bahamas, Hawai'i for Americans and the northern Red Sea for Europeans). If they're among the few who have actually been to a real reef, they're likely to have a skewed idea of what "typical" reef temps are like.
Mike G.
Ha'ina 'ia mai ana ka puana.
|
|
|
|
|
Group: Forum Members
Last Login: 2 days ago @ 3:12:13 AM
Posts: 374,
Visits: 1,803
|
|
Ugh, the inability to edit posts is frustrating.
Meanwhile the same species in my personal tanks would rarely see summer temps below 82 without issue.
As it's written this is confusing. What I meant is that it was rare that these animals in my personal tank would see temperatures below 82 during the summer and there were no obvious issues. In constrast, the animals I work with show severe stress at 82 which is about 4 degrees above their normal summer maximum and kept at that temp long enough they bleach.
Mike G.
Ha'ina 'ia mai ana ka puana.
|
|
|
|
|
Group: Forum Members
Last Login: Today @ 1:11:55 AM
Posts: 777,
Visits: 3,828
|
|
i am reading " A Reef in Time" by J.E.N. Veron right now. he states that the ideal reef temp is 27 degrees C which translates to 80.6F this is for the GBR and he says "for all metabolic processes, photosynthesis and calcification proceed at an optimal rate at this temp. if the temp is higher than that, the rate of these metabolic activities is accelerated in an increasingly uncontrolled way."
great read btw. i still have a lot more pages to go but i am starting to feel even more guilt about my contributions to global warming than i was.
a lot of science but written so that even i can understand it so far.
------------------------------------
Carl
"almost any obstacle can be overcome with information; information is truly the oxygen of understanding."
Anthony Calfo
Going Solar
|
|
|
|
|
Group: Moderators
Last Login: Yesterday @ 4:45:05 AM
Posts: 3,970,
Visits: 5,890
|
|
For reefs worldwide the average is 82.7-85.1F and this includes outliers (high latitutude, etc). The center of coral biodiversity is what Chuck mentions and this is also where most of our corals come from.
The story of transplantation studies, interrelationships with light and temperature and salinity, variations in thermal tolerance/acclimitazation, ability to upregulate hsps, symbiont variations, across space and time, and other points Mike makes are valid, but not written in stone. May corals, even in areas of high average annual temps may experience warming and cooling far above their norms without obvious detriment (upwellings, lagoons, thermoclines, etc.). There are synergistic effects with temp, and clealry seasonal variations (high lat reefs can become quite cold in winter and quite warm in summer - generally hotter and colder than more equatorial reefs.
I do agree it is largely a matter of holdover from years past, and I also think that if temps are very stable there is not necessaily less wiggle room for some species, but if variations in the tank are normal, I think there is. And an upper thermal limit can be established although it too varies according to place - in the example Mike uses, Pocillopora, Eastern Pacific and Easter Island reefs have low tolerance for temp increases and would not do well if put into the 88-90 water where they are also found (i.e. area of the Red Sea, central I-P lagoons with low water flux). Same species, different "wiggle room" but perhaps able to be acclimtized over time.
______________________
|
|
|
|
|
Group: Forum Members
Last Login: 6/25/2008 11:56:35 PM
Posts: 13,
Visits: 58
|
|
| Carl, I am fairly certain that if your reflective material does not go down to the top of your tank, by mid winter you will have a well lit living room but none in the tank even at mid day. At my latitude, mid winter sun comes in at 45% at mid day. You will almost definately be further from the equator. Thus with your reflector 400-500mm off the tank, even a meter wide tank will get its side glass lit, and the rest on the living-room floor. I think that as well as this you need to think about fins in the shaft to defuse the beam a bit, or you will always have half the tank brightly lit and the other with only very little light. I think that you reflective material is doing too good of a job with your beam of light, and that it needs to be broken up a bit. With adjustable or even non-ajustable fins at the top you could angle them so that light is not bouncing around the tunnel so much and heads more straight down.
|
|
|
|
|
Group: Forum Members
Last Login: 6/25/2008 11:56:35 PM
Posts: 13,
Visits: 58
|
|
| Carl, my last post seemed a little critical, it was not intended to be, I hope it was not taken that way. A possibly interesting observation. A vase of roses, bought for Eric's visit, and placed in the big void where the tank will be, is now three weeks old. Normally we're lucky if they last one week. I put it down to the fact that its getting good light, the leaves are photosynthisysing, and they have energy to open up properly, yesterday after virtually three weeks two flowers opened up beutifully. I don't know how exactly that translates to success with corals, but both roses and many corals need lots of light.
|
|
|
|
|
Group: Moderators
Last Login: Yesterday @ 4:45:05 AM
Posts: 3,970,
Visits: 5,890
|
|
Rob, you bought us roses? We had no idea! Thank you. 
The use of a potted plant that thrives in bright sunlight is probably not a bad way to pre-assess light. I hadn't though of that before. Not as accurate as a PAR meter, though. Rob, you and some of the guys in Jo-berg really should pitch together and buy an Apogee PAR meter and you can all use it since you don't need to be measuring all the time. For you, especially, it would be really helpful in "tuning" your light especially with your proposed use of the gels.
______________________
|
|
|
|
|
Group: Forum Members
Last Login: 6/25/2008 11:56:35 PM
Posts: 13,
Visits: 58
|
|
| Yup, Carls planning had you staying, he just neglected to tell you guys. Had a whole fridge of veggies too. Regarding the light meter, I have my Appogee on the way, one that can do sun and electric light. I will really need it with placement in this tank.
|
|
|
|
|
Group: Forum Members
Last Login: Today @ 1:11:55 AM
Posts: 777,
Visits: 3,828
|
|
Rob, no offense taken. the light is distributed more evenly than you think, at least over the course of the day. although at any given time there may only be an area that is brightly lit. at mid day the tank is pretty evenly lit. i have thought of adding baffles inside the shaft but it seems like a lot of work and it would make it harder to work on the tank too, which is going to be difficult enough. and i may have some lights over the tank eventually.
most corals on the reef are also shaded during different parts of the day.
i am at 36-37 degrees latitude here in los Angeles. although the days are shorter and the angle of the sun is less we still have many sunny days in the winter. actually probably more than at this time of year. this time of year we have most day for the next couple of months start out overcast in the morning and then it gets sunny by noontime. i am about 3 miles from the beach.
i would like to see you start a build thread so we can follow your progress. i am very interested to see what you do.
what are you lining your shaft with? what is the size of the shaft and tank?
------------------------------------
Carl
"almost any obstacle can be overcome with information; information is truly the oxygen of understanding."
Anthony Calfo
Going Solar
|
|
|
|
| |