Common Misconceptions In the Hobby

<a href=showthread.php?s=&postid=12114717#post12114717 target=_blank>Originally posted</a> by fred fishstone
Every couple of weeks I put a 100 micron filter bag on my drain line, and use a sea-squirt feeder (long skinny turkey baster) to stir up the shallow (about 1") sand bed. It really does seem to make the corals happy. Of course I have to blow off the rocks a few times after that, but then everything settles back to normal. I'm glad to hear that it may have a long-term benefit!

i've been doing that too--just on the surface however--so this is good to know
 
Capn I am no expert on DSBs as I have not ran one since the seventees and it crashed.
If I were you I would clean the glass under the sand in the front with a rasor blade so as not to disturb too much sand. That is the reason I do not like DSBs.
They are designed to fail eventually, you can't invigorate it or clean it.
 
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This thread has been very educational and has cleared up some questions I have had thanks to all of the input from many sources. I prefer to come up with my own conclusoins many times but I always base them on input from many different sources of many levels of experience.
 
<a href=showthread.php?s=&postid=12120235#post12120235 target=_blank>Originally posted</a> by Paul B
Capn I am no expert on DSBs as I have not ran one since the seventees and it crashed.
If I were you I would clean the glass under the sand in the front with a rasor blade so as not to disturb too much sand. That is the reason I do not like DSBs.
They are designed to fail eventually, you can't invigorate it or clean it.

what I understand from reading Shimek
http://reefkeeping.com/issues/2003-06/rs/feature/index.php

that whether it is dsb or 3-5 inch sb the first two out of three biotic areas are probably the most importan and they occur in the first inch of the sand base. Stirring the first inch then can be very adventageous to stimulating and supporting new life.

Am I on track here?
 
I read a similar article in the late 90's and subscribed ever since. I have been very happy with the SSB in my current tank. Nitrates have always been ND (4 years). I've recently started feeding MUCH (!!!!) more though...but I started dosing carbon concurrently so I have little way of knowing if it's the SSB or the carbon handling the NO3. Two ideas...

1) NO3 being kept in check by the SSB and PO4 by the GFO
or
2) The first scenario is correct but it's being augmented by the increased bacteria growth due to the carbon (vodka/vinegar/sugar mixture).

I think #2 is MUCH more likely.
 
<a href=showthread.php?s=&postid=10597601#post10597601 target=_blank>Originally posted</a> by Peter Eichler
17ish.) You should test for nitrites regularly since they are toxic to saltwater aquarium inhabitants.

Nitrites will only cause apparent stress in most saltwater fish and invertebrates at VERY high levels. Some marine fish and invertebrates have shown to be tolerant of nitrite well in excess of 1000ppm.

Conclusion: After the initial nitrogen cycle is complete there is little to no reason to ever test for nitrites again in a marine aquarium.
Peter thanks, very nice thread. But I will debate you on one thing, comparing natural conditions to captivity conditions may require a different captivity environment. For example a fish exposed to 500ppm of nitrate in the wild, may also burn toxins after swimming free for miles, where in the fish tank the inhabitants don't get so much swimming area. In the wild when the temperature swings 5 deg they also may have better oxygen. Another one, is our lighting anything close to natural lighting? do we know if MH bulbs are ,missing some kind of lighting element ? again thanks for the post.
 
In the wild when the temperature swings 5 deg they also may have better oxygen.
There's somewhat of a misconception right there. Over the range from 76-86, where most reef tanks fall, the effect of temp on oxygenation is essentially negligible. By keeping your tank at 76 rather than 86 you increase the saturation point by a whopping 7.5%. Eric Borneman did tests several years ago testing a variety of "typical" tanks and they came in at ~70-95% saturated. So at 86 degrees and 70% saturation you're still looking at 150% of the minimum acceptable longterm DO. As it turns out though, many reef animals, including corals and all of the fish that have been looked at so far are tolerant of at least short periods (several hours) of DO concentrations down to 20%, many even lower than that.

So how does that compare to the real world? It's actually pretty close. The water above the reef ranges from about 80-110% saturated, so very comparable to our tanks. The water near the substrate and corals is often 40-<5% at night, so again, it's unlikely that our tanks have significantly less DO than that.

There's another factor that plays into all of this though, and that's the increase of metabolism with increasing temperature. As it turns out, there isn't this clean, direct correlation between metabolic rate and temperature like a lot of people learn in freshman biology or ecology. Acclimatization actually ends up playing a big factor. In most of the reef animals that have been studied, when they're from environments that have a wide range of temps, there's only a very slight increase of metabolism with increasing temperature until some critical high value (usually much higher than we would ever let our tanks go). Animals from a stable environment have a much narrower range of temperatures where their metabolism is roughly the same. Basically as the temp increases, their respiration shoots up due to metabolic stress and looks much more like the traditional profile for coldblooded animals.

So what does all of this mean? It means that if keeping your tank at 76 rather than 86 or any variation in between has a noticeable effect on your oxygenation, you have much bigger problems than the temperature. Even in the case of an emergency, hypoxia occurs so fast (on the order of a couple of minutes) in stagnant water that the amount of time you buy yourself by keeping things cooler is essentially meaningless.
 
Greenbean--if you wouldn't mind applying this to a situation where there is a power failure in a winter climate where the tank temp starts to fall. What exactly starts to occur in the water and to the fish metabolically?
 
I don't know if anyone ever checked, but maybe coral like beer too?

Copperbands seem to like it
13094Bud_can_and_copperband.jpg
 
What exactly starts to occur in the water and to the fish metabolically?

I will let Greenbean answer this but I will say that colder water holds more oxygen (and other gasses) which would seem better for fish but cold blooded fish also slow down their metabolism in colder water so they need less oxygen anyway so the extra oxygen does not help them much. A fish depends on the temp of the water to control their metabolism just like we depend on our internal temperature to control ours. If our internal temperature changes even by a degree or two we feel lousy. A fish has a little more tolerance then us because they have evolved in a changing envirnment which is subject to Mother nature but after a point, a tropical fish will be severly stressed as the water chills. They will slow down and probably lay on the bottom. Eventually their breathing slows so much that the fish dies.
In warmer water a fish metabolism forces the fish to burn energy faster causing it to breathe faster. Warmer water holds less oxygen and eventually the fish will not be able to extract enough oxygen and it will also die. In the Long Island Sound where I boat and dive we have massive fish kills almost every year due to warming of the water. Another factor is Red Tide which is paracites that block the fish gills making it even harder for the fish to breath. We get dead fish starting at shore extending out about a quarter mile with no clear water in between, just dead fish.
 
<a href=showthread.php?s=&postid=12129278#post12129278 target=_blank>Originally posted</a> by Paul B
I will let Greenbean answer this but I will say that colder water holds more oxygen (and other gasses) which would seem better for fish but cold blooded fish also slow down their metabolism in colder water so they need less oxygen anyway so the extra oxygen does not help them much. A fish depends on the temp of the water to control their metabolism just like we depend on our internal temperature to control ours. If our internal temperature changes even by a degree or two we feel lousy. A fish has a little more tolerance then us because they have evolved in a changing envirnment which is subject to Mother nature but after a point, a tropical fish will be severly stressed as the water chills. They will slow down and probably lay on the bottom. Eventually their breathing slows so much that the fish dies.
In warmer water a fish metabolism forces the fish to burn energy faster causing it to breathe faster. Warmer water holds less oxygen and eventually the fish will not be able to extract enough oxygen and it will also die. In the Long Island Sound where I boat and dive we have massive fish kills almost every year due to warming of the water. Another factor is Red Tide which is paracites that block the fish gills making it even harder for the fish to breath. We get dead fish starting at shore extending out about a quarter mile with no clear water in between, just dead fish.

Yes, Paul and this is the biology that I learned but greenbean does not agree--quoted from his last post

"There's another factor that plays into all of this though, and that's the increase of metabolism with increasing temperature. As it turns out, there isn't this clean, direct correlation between metabolic rate and temperature like a lot of people learn in freshman biology or ecology. Acclimatization actually ends up playing a big factor. In most of the reef animals that have been studied, when they're from environments that have a wide range of temps, there's only a very slight increase of metabolism with increasing temperature until some critical high value (usually much higher than we would ever let our tanks go). Animals from a stable environment have a much narrower range of temperatures where their metabolism is roughly the same. Basically as the temp increases, their respiration shoots up due to metabolic stress and looks much more like the traditional profile for coldblooded animals."
 
<a href=showthread.php?s=&postid=12129201#post12129201 target=_blank>Originally posted</a> by Paul B
Copperbands seem to like it
13094Bud_can_and_copperband.jpg

mine don't get a chance to try it and find out
:beer:

now I know the secret behind the 30 yr longevity of your tank

its well polluted er well preserved er sloshed out weekly er kept in high spirits er:lol:

that's why reef keeping is a slam dunk er slam drunk for you.:D
 
As it turns out, there isn't this clean, direct correlation between metabolic rate and temperature like a lot of people learn in freshman biology or ecology

Capn, luckily for me I diden't learn about fish from a biology class.
I have been in the water with them for many years and not just as a resort diver. I have my own boat and equipment so I can stay down as long as I like to study them.
Greenbean is a student and he probably knows more about metabolic rate and temperature than I do.
I do know from observation that fish breathe faster in warmer water. It may be a slight acceleration as Bean says but as a cold blooded animal they do breath faster. I would imagine that because colder water holds more oxygen it would temper the breathing somewhat because the fish gets more oxygen with each gill movement, but if we could get the same oxygen level in water's of varying temperatures I believe that fish would breathe faster in warmer water.
Of course that is just my un educated guess
 
<a href=showthread.php?s=&postid=12131294#post12131294 target=_blank>Originally posted</a> by Paul B
Capn, luckily for me I diden't learn about fish from a biology class.
I have been in the water with them for many years and not just as a resort diver. I have my own boat and equipment so I can stay down as long as I like to study them.
Greenbean is a student and he probably knows more about metabolic rate and temperature than I do.
I do know from observation that fish breathe faster in warmer water. It may be a slight acceleration as Bean says but as a cold blooded animal they do breath faster. I would imagine that because colder water holds more oxygen it would temper the breathing somewhat because the fish gets more oxygen with each gill movement, but if we could get the same oxygen level in water's of varying temperatures I believe that fish would breathe faster in warmer water.
Of course that is just my un educated guess

maybe we can get the "great bean" to reply here;)

thanks for participating in the other thread:smokin:
 
Yep, the simple version is that enzymes catalyze metabolic chemical reactions and as the temperature increases those reactions speed up just like most chemical reactions. As the temp keeps increasing you eventually get to a maximum temp, after which the catalytic enzyme starts to denature and lose functionality. At that point the rate drops off dramatically.

The real world is a lot more complicated than that though. You could literally write volumes on the subject and many people have spent their entire careers working out what exactly is going on. The short version of the long story is that there's a range of temperatures where you hover around the same maximum rate because there are multiple versions of the rate defining enzymes. In a hypothetical critter you would have one version of an enzyme that maxes out between 78-80, one between 80-83, and one between 81-85, all of which work at roughly the same maximum rate. As the temp increases from 78-85, which enzyme is carrying the bulk of the load changes, but since you're already near the max rate for all the forms you end up getting a plateau over that range rather than increasing much more. Beyond that range, repair mechanisms take over and you get a slight increase before things start going back downhill fast.

The different isoforms of the enzymes also play into the acclimatization issue because the relative proportions of the different forms in the enzyme pool change over time. If it's always 78, then the animal stops wasting resources making the other forms that it doesn't need and devotes almost everything to the 78 degree form. That ends up being a gamble though because as long as everything stays the same that works out great, but if things change you don't have a very large pool of the enzymes you need and things get bad in a hurry.
 
<a href=showthread.php?s=&postid=12131812#post12131812 target=_blank>Originally posted</a> by greenbean36191
Yep, the simple version is that enzymes catalyze metabolic chemical reactions and as the temperature increases those reactions speed up just like most chemical reactions. As the temp keeps increasing you eventually get to a maximum temp, after which the catalytic enzyme starts to denature and lose functionality. At that point the rate drops off dramatically.

The real world is a lot more complicated than that though. You could literally write volumes on the subject and many people have spent their entire careers working out what exactly is going on. The short version of the long story is that there's a range of temperatures where you hover around the same maximum rate because there are multiple versions of the rate defining enzymes. In a hypothetical critter you would have one version of an enzyme that maxes out between 78-80, one between 80-83, and one between 81-85, all of which work at roughly the same maximum rate. As the temp increases from 78-85, which enzyme is carrying the bulk of the load changes, but since you're already near the max rate for all the forms you end up getting a plateau over that range rather than increasing much more. Beyond that range, repair mechanisms take over and you get a slight increase before things start going back downhill fast.

The different isoforms of the enzymes also play into the acclimatization issue because the relative proportions of the different forms in the enzyme pool change over time. If it's always 78, then the animal stops wasting resources making the other forms that it doesn't need and devotes almost everything to the 78 degree form. That ends up being a gamble though because as long as everything stays the same that works out great, but if things change you don't have a very large pool of the enzymes you need and things get bad in a hurry.

thanks greenbean always appreciate your input as I have your mentoring:smokin:

could you possible add some input on this thread:

http://reefcentral.com/forums/showthread.php?s=&threadid=1349443
 
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