vitz
New member
even though it doesn't get food in my belly, or get the dirt out of my carpet, i always feel better after opening a window in a stale room.
I don't do water changes
- Thread starter houstonhobby
- Start date
even though it doesn't get food in my belly, or get the dirt out of my carpet, i always feel better after opening a window in a stale room.
it's pretty much agreed upon that THE MAIN driver of bleaching events is higher long term, and 'short term spike' temperatures.
That's your current opinion but not a consensus by any means and it doesn't jibe with our original statement about light and nutrients which was unequivocal . In post #253 you said:
bleaching events in the wild have nothing to do with light, and probably very little to do w/ nutrients.
it's a heat induced phenomenon.
Temperature may or may be a significant trigger in some or even the majority naturally occuring bleaching events . It will in reeftanks as will rapid increases in light intensity.
many of those claiming it to be 'sunspots' or some other 'pulled out of a hat' theory seems to be more oil industry shills from other disciplines than actual coral scientists/biologists/researchers.
No that's not the case at all .
Here a few research related non oil industry publications that show consensus for multiple causative factors for bleaching including temperature, light and nutrient levels:
http://www.sciencedaily.com/releases/2012/08/120819153617.htm- interesting twist exploring nuteint excess and limitation with an effect on zooxanthellae . Ties in nicely with a number of nutient "fixing" ,ie, balancing techniques being explored by some in the hobby
http://www.marinebiology.org/coralbleaching.htm-nice summary on temp and global warming trends, solar irradiance and nuteint issues as causative.
http://www.science.org.au/nova/076/076key.html
http://oceanservice.noaa.gov/facts/coral_bleach.html this one is short and sweet;from it:
When corals are stressed by changes in conditions such as temperature, light, or nutrients, they expel the symbiotic algae living in their tissues, causing them to turn completely white.
Sorry about the font size; that's how it copied.
There are many more sources.
It's not all about temperature and the consensus at least in the reading I've done through the years is that increased light intensity can cause bleaching.
I'm not interested in turning this into a political discussion on global warming, climate change , solar activity , oil companies etc.Though I have my opinions expressing them here would not be appropriate or useful. I'm focused on how things work.
In a reef tank, I've taken bleached corals from a friend's tank that were overexposed to new lighting and put them under low er light in my system for a week or so and have been pleasantly surprised with their recovery and coloration after a few weeks.
That's your current opinion but not a consensus by any means and it doesn't jibe with our original statement about light and nutrients which was unequivocal . In post #253 you said:
bleaching events in the wild have nothing to do with light, and probably very little to do w/ nutrients.
it's a heat induced phenomenon.
Temperature may or may be a significant trigger in some or even the majority naturally occuring bleaching events . It will in reeftanks as will rapid increases in light intensity.
many of those claiming it to be 'sunspots' or some other 'pulled out of a hat' theory seems to be more oil industry shills from other disciplines than actual coral scientists/biologists/researchers.
No that's not the case at all .
Here a few research related non oil industry publications that show consensus for multiple causative factors for bleaching including temperature, light and nutrient levels:
http://www.sciencedaily.com/releases/2012/08/120819153617.htm- interesting twist exploring nuteint excess and limitation with an effect on zooxanthellae . Ties in nicely with a number of nutient "fixing" ,ie, balancing techniques being explored by some in the hobby
http://www.marinebiology.org/coralbleaching.htm-nice summary on temp and global warming trends, solar irradiance and nuteint issues as causative.
http://www.science.org.au/nova/076/076key.html
http://oceanservice.noaa.gov/facts/coral_bleach.html this one is short and sweet;from it:
When corals are stressed by changes in conditions such as temperature, light, or nutrients, they expel the symbiotic algae living in their tissues, causing them to turn completely white.
Sorry about the font size; that's how it copied.
There are many more sources.
It's not all about temperature and the consensus at least in the reading I've done through the years is that increased light intensity can cause bleaching.
I'm not interested in turning this into a political discussion on global warming, climate change , solar activity , oil companies etc.Though I have my opinions expressing them here would not be appropriate or useful. I'm focused on how things work.
In a reef tank, I've taken bleached corals from a friend's tank that were overexposed to new lighting and put them under low er light in my system for a week or so and have been pleasantly surprised with their recovery and coloration after a few weeks.
vitz
New member
your bolded statements say nothing about relative effect or importance between the factors. rest assured they are far from equal,which is indeed the case, and the point i was trying to convey. i don't think there's a reputable coral scientist on the planet that would contend that the increase in bleaching events worldwide isn't mainly a result of changing (measured and verified) ocean temp maximum's.
and on corl-list, at the least, it appears to be the consensus.
blanden.adam
Team RC
Perhaps that's what you meant, but I think if you read your post that's not what you actually said -- you used very definitive language that excluded the other sources. I think an important thing to consider that because of global climate change, the entire ocean is increasing in temperature and CO2 content. Most areas are not experiencing large changes in light, nutrient levels, etc. So although the other sources may effect corals adversely to an equal or even greater degree on a case-by-case basis, just by sampling bias temperature would be the major player.
At any rate I don't think the two points are diametrically opposed.
rickcasa
New member
Precisely...NO3 and PO4. I guess I just want to be gentler with the effects of a large wc, be it that they be positive, to my livestock. Point taken though on the diminishing returns of a weak wc ratio. I guess only salt is wasted if I draw it out over 2 weeks as opposed to in a couple days but maybe 50% as the first change in 7 months may be better. Sorry NoWC advocates for caving as I believe my inner chemist was challenged with the minutiae of water condition testing and balancing act. I just want the coolest tank I can practically manage with a growing family!
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power boat jim
Well-known member
You use cheto gfo, and a skimmer but say the need to do water changes is a sign of problems that need to be addressed. I only use a skimmer and water changes. I have no need for the other two methods you use for nutrient control. It appears by your logic there is something wrong with my tank. Yet, I use two less devices for nutrient control then you do.
Please explain to me what logic you used to come up with the water change theory.
jimmyj7090
aka John K
Maybe an issue of too much inport?
My system maintains low nitrate and phosphate with good skimming, a slight daily dose of vinegar and very light feeding. If I kept everything the same but added 3x more fish and 4x more feeding I would expect the nitrate and phoshpate to start accumulating
power boat jim
Well-known member
Maybe an issue of too much inport?
My system maintains low nitrate and phosphate with good skimming and a slight daily dose of vinegar and very light feeding. If I kept everything the same but added 3x more fish and 4x more feeding I would expect the nitrate and phoshpate to start accumulating
Same could be said for the need to use vinegar, gfo, vodka or any other artificial nutrient control. I just dont see the difference of why using one indicates a problem and the others dont.
jimmyj7090
aka John K
I agree.
Unless I misunderstood earlier, the "problem" would be nutrient import and export being out of balance resulting in accumulating nitrate and phosphate that need to be managed through water changing. In my own thinking, my goal is to keep import and export balanced so that my only need for water changing it to replenish micronutrients and correct anything else that I cannot accurately monitor or supplement. That sort of goes back to the initial discussion from the first pages of this thread. (the OP started it testing the premise that needing water changs indicated a problem and not changing would indicate a well managed system, IIRC after some discussion the OP changed their stance and agreed that water changes could/would be benifical for reasons other than nutrient control)
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SpartaReef
New member
A large water change when you haven't done any could shock your system... I would start with very small wc's, one every two days for a week then taper off to fewer changes a week/2weeks at larger ratios
jimmyj7090
aka John K
I do > %50 water changes and nothing in the tank seems to react in any way. (water changes done via dual head peristaltic pump, circulation never shuts off, water changes take about an hour).
If the new water isn't matched on the main numbers (alk, ca, mg, SG, temp) it will cause a lot of stress. If those numbers are well matched, big water changes are quite smooth
If the new water isn't matched on the main numbers (alk, ca, mg, SG, temp) it will cause a lot of stress. If those numbers are well matched, big water changes are quite smooth
DavidinGA
Active member
The widely help belief in doing water changes is that they are necessary to remove nutrients that can not be removed any other way; from that standpoint their is a flaw in how nutrients are handled within a system. If you realize their are ways to control nutrient buildup and you choose not to use them and go the water change route instead that's great but it's still not necessary had you used those other tools.
SpartaReef
New member
I do > %50 water changes and nothing in the tank seems to react in any way. (water changes done via dual head peristaltic pump, circulation never shuts off, water changes take about an hour).
If the new water isn't matched on the main numbers (alk, ca, mg, SG, temp) it will cause a lot of stress. If those numbers are well matched, big water changes are quite smooth
But you do regular water changes.... He hasn't done any.... A sudden massive water change could cause a shift in the parameters
power boat jim
Well-known member
Any method you use to lower nutrients is a tool. Be it water change cheto or anything else. I just dont believe using any of them is any better or worse then any other. Having to use them at all is an indictment that there is an imbalance in the system. How we choose to handle it is nothing more then doing whats easiest for each of our systems to maintain a balance.
jimmyj7090
aka John K
I do them every 6 months or so. No evident shock or stress.
SpartaReef
New member
Ok. Ive done a few massive (50%+) water changes vs the usual 15% that I do... Yeah it shocks the algae, everything else loves it....
vitz
New member
I do > %50 water changes and nothing in the tank seems to react in any way. (water changes done via dual head peristaltic pump, circulation never shuts off, water changes take about an hour).
If the new water isn't matched on the main numbers (alk, ca, mg, SG, temp) it will cause a lot of stress. If those numbers are well matched, big water changes are quite smooth
this
Well, I never said temperature is not a trigger for bleaching,perhaps even a more common one. Never mentioned sun spots either. Temperature can be a factor when it goes up or down suddenly for sure. I've already said that. I do say light is also a factor mentioned in virtually every accounting of coral bleaching . It does have something;not nothing, to do with bleaching in the wild or in a reef tank. Unusually low tides can result in increased temperatures from more irradiation and expose corals to more photosynthetically available radiation and uv effects as well. Excess nutients and even nutrient limitations play a role.
Your claim to consensus regarding temperature exclusive of light effects from the coral list ,a NOAA(National Ocean and Athmospheric Administation) forum, is curious, since the last of 4 cites I provided in my earlier post is from NOAA and clearly the summary statement does not discount light as a factor in bleaching events.
vitz
New member
coral-list isn't exactly noaa. it's sponsored and maintained by noaa. there are often critiques of noaa and many other agencies on coral-list. fwiw, if you're not already subscribed, and can ignore some of the all too common 'infighting among scientists', it's a great source of info for alot of the real world events going on re: bleaching and bleaching forecasts/discussions. as they happen. i've yet to read ANYTHING regarding light as a consideration, not by the individuals in the field, or those campaigning for saving the reefs/mitigating damage to them. just sayin'.
just because someone can cause a coral to bleach in an aquarium by improper light acclimation, doesn't mean it either happens in the wild, or is a trigger in the wild. not all induce-able phenomena 'in vitro' are of a real or practical concern 'in situ', and vice versa. temperature, on the other hand, is verifiable quite easily for both. (as is pollution and sedimentation) it also doesn't jive w/people who keep 400 watts of light or more over shallow tanks. (i've kept corals w/ 300 watts of halide mounted 4" above water surface in a 20 long. by all accounts, they should have been toast, if light is a bleaching factor.) i know people who've gone above that wattage/intensity, with a relatively small increase in water height w/ no issues whatsoever.
if light was truly a repeatable main or even common, cause/stressor, i really really doubt that soooo many sps corals would survive a low tide in full equatorial/semi equatorial sunlight without the radiation absorbing protection of water during low tides. especially when that change occurs in a matter of hours or less,( sometimes minutes) and with great frequency. it just doesn't add up to simple observation in situ. if it was the cause of bleaching at 10' depth, it should certainly wipe out everything at a 6" depth, and that doesn't happen. it HAS to be a teeny teeny factor.
one of your links is '404' btw, one only mentions an increase in uv radiation as your 'solar irradiance' factor. which is also an 'artificial' condition brought upon by us, very recently by coral's 'standards' of evolution. that doesn't mean that coral's are damaged by uv radiation under 'normal' natural conditions. and given the relatively poor penetration of uv through saltwater, the argument seems to me to 'hold even less water', given the depths at which bleaching is observed. iirc, uv penetration through light is extremely poor, and rises sharply as the wavelength gets shorter
('solar irradiation' imo is way too broad a term/category to use-it's a blanket term for the entire energy spectrum of the sun. mebbe x-rays should be looked into as well? what about infra red? maybe some of the radiations that get past the van allen belts are a cause too! ).
there are people who've been looking at reefs extensively from back in the day that never really observed/reported mass bleaching events. most of them, afaict, blame temp and pollution/sedimentation, NOT uv or light energy increases.
from one of your links:
"Other causes of coral bleaching
Apart from heat stress, other causes of coral bleaching may include:
increased exposure to ultraviolet (UV) radiation;
large amounts of storm water from heavy rains flooding the reef;
the exposure of coral to certain chemicals or diseases;
sediments such as sand or dirt covering the coral;
excess nutrients such as ammonia and nitrate from fertilisers and household products entering the reef ecosystem. (The nutrients might increase the number of zooxanthellae in the coral, but it is possible that the nutrient overload increases the susceptibility of coral to diseases.)
Often coral reefs are exposed to a combination of these factors."
that page isn't exactly a discussion between scientists in the field
i'm still stickin to mah guns re: light as a complete non factor in coral bleaching in nature, (maybe LACK of light from sedimentation is) and that such a thing never happened,(certainly not en masse), after coral's evolved to their present day form/adaptations. imo it's a silly 'hypothesis'. temp is clear cut and obvious, proven both in the wild and captivity. it's clearly THE main cause/factor in coral bleaching. nor have i ever seen light mentioned in an actual accounting of an actual event. lighting is only mentioned in general as a 'known factor' on pages like your link i quoted,(not exactly an 'accounting'), never as an observed quality that increased somehow in an area.
how on earth would light on a full sunny day suddenly increase over any area compared to the full sunny day the day before or after ? temp increases from light isn't the same as light. to say that light induced temp. effects on coral (shallow water exposure/differences from deeper water)= light's effects on corals is silly, imo.
it's sponsored and maintained by noaa. there are often critiques of noaa and many other agencies on coral-list. fwiw, if you're not already subscribed, and can ignore some of the all too common 'infighting among scientists', it's a great source of info for alot of the real world events going on re: bleaching and bleaching forecasts/discussions. as they happen. i've yet to read ANYTHING regarding light as a consideration, not by the individuals in the field, or those campaigning for saving the reefs/mitigating damage to them. just sayin'.just because someone can cause a coral to bleach in an aquarium by improper light acclimation, doesn't mean it either happens in the wild, or is a trigger in the wild. not all induce-able phenomena 'in vitro' are of a real or practical concern 'in situ', and vice versa. temperature, on the other hand, is verifiable quite easily for both. (as is pollution and sedimentation)
it also doesn't jive w/people who keep 400 watts of light or more over shallow tanks. (i've kept corals w/ 300 watts of halide mounted 4" above water surface in a 20 long. by all accounts, they should have been toast, if light is a bleaching factor.) i know people who've gone above that wattage/intensity, with a relatively small increase in water height w/ no issues whatsoever.if light was truly a repeatable main or even common, cause/stressor, i really really doubt that soooo many sps corals would survive a low tide in full equatorial/semi equatorial sunlight without the radiation absorbing protection of water during low tides. especially when that change occurs in a matter of hours or less,( sometimes minutes) and with great frequency. it just doesn't add up to simple observation in situ. if it was the cause of bleaching at 10' depth, it should certainly wipe out everything at a 6" depth, and that doesn't happen. it HAS to be a teeny teeny factor.
one of your links is '404' btw, one only mentions an increase in uv radiation as your 'solar irradiance' factor. which is also an 'artificial' condition brought upon by us, very recently by coral's 'standards' of evolution. that doesn't mean that coral's are damaged by uv radiation under 'normal' natural conditions. and given the relatively poor penetration of uv through saltwater, the argument seems to me to 'hold even less water', given the depths at which bleaching is observed. iirc, uv penetration through light is extremely poor, and rises sharply as the wavelength gets shorter
('solar irradiation' imo is way too broad a term/category to use-it's a blanket term for the entire energy spectrum of the sun. mebbe x-rays should be looked into as well? what about infra red? maybe some of the radiations that get past the van allen belts are a cause too!
).there are people who've been looking at reefs extensively from back in the day that never really observed/reported mass bleaching events. most of them, afaict, blame temp and pollution/sedimentation, NOT uv or light energy increases.
from one of your links:
"Other causes of coral bleaching
Apart from heat stress, other causes of coral bleaching may include:
increased exposure to ultraviolet (UV) radiation;
large amounts of storm water from heavy rains flooding the reef;
the exposure of coral to certain chemicals or diseases;
sediments such as sand or dirt covering the coral;
excess nutrients such as ammonia and nitrate from fertilisers and household products entering the reef ecosystem. (The nutrients might increase the number of zooxanthellae in the coral, but it is possible that the nutrient overload increases the susceptibility of coral to diseases.)
Often coral reefs are exposed to a combination of these factors."
that page isn't exactly a discussion between scientists in the field
i'm still stickin to mah guns re: light as a complete non factor in coral bleaching in nature, (maybe LACK of light from sedimentation is) and that such a thing never happened,(certainly not en masse), after coral's evolved to their present day form/adaptations. imo it's a silly 'hypothesis'. temp is clear cut and obvious, proven both in the wild and captivity. it's clearly THE main cause/factor in coral bleaching. nor have i ever seen light mentioned in an actual accounting of an actual event. lighting is only mentioned in general as a 'known factor' on pages like your link i quoted,(not exactly an 'accounting'), never as an observed quality that increased somehow in an area.
how on earth would light on a full sunny day suddenly increase over any area compared to the full sunny day the day before or after ? temp increases from light isn't the same as light. to say that light induced temp. effects on coral (shallow water exposure/differences from deeper water)= light's effects on corals is silly, imo.
