Common Misconceptions In the Hobby

[greenbean36191]

Warm surface water over cool deep water forms a thermocline, or a rapid change in temperature in these areas. This acts as a "cap", preventing upwelling from supplying these areas with nutrients which phytoplankton need to grow.

We know now that this isn't exactly true. We don't see the constant, margin-wide upwelling on the western side of oceans, but now we know that upwelling of sub-thermocline water is frequent on western margins, including most reefs and probably plays an important role in nutrient influx. The difference is that on the western side of basins the upwellings are pulsed so the nutrients aren't available all the time to cause phyto blooms.

Regardless, I agree that phyto density is relatively low on reefs and the idea that phyto is the base of the food chain is erroneous. Primary producers are the base of the food chain, but that includes benthic algae too. Lots of animals feed on benthic algae as adults and then their larvae either don't feed at all in the plankton or feed on smaller zooplankton without phytoplankton ever entering into the equation.

I think it's also important to distinguish between feeding on phyto facultatively vs. constituatively, i.e. whether an animal needs to feed on phytoplankton or will eat it if it's available. Most of the critters in our tanks fall into the latter. You can give them more food and make them bloom, but beyond anecdotal reports that corals look healthier etc. I don't know of any great strong reason to believe those blooms are of any great benefit to our tanks.

Ultimately plankton is a tricky word as everything is ultimately subject to dispersal by water movements. What changes is how affected the organism is and how strong the water movement must be. So, a copepod in your sump may not be considered planktonic, however in your turbulent DT it may be...The same applies for reefs.

Usually any animal that can swim against a 1 kt current isn't considered plankton. An animal that doesn't normally spend a significant portion of its life suspended in the water also usually isn't called plankton, so the benthic copepods, even if they do get swept up, aren't really plankton by most definitions.

I would be extremely surprised to find any significant amount of zooplankton in a reef tank unless you happened to sample right after a spawning event.

 

[Aquarist007]

This is the only way I can do this without hijacking:

Greenbean and Paul--can you take a look at my prize Lord--and see what the problem is:

http://www.reefcentral.com/forums/showthread.php?s=&threadid=1272061

 

[Aquarist007]

<a href=showthread.php?s=&postid=11386424#post11386424 target=_blank>Originally posted</a> by Paul B
Capn, thanks, today i finished my Captains upgrade to 100 tonns.
Maybe I will take you out SCUBA diving.
Paul
:lol:

deal:smokin:

 

[Aquarist007]

<a href=showthread.php?s=&postid=11387168#post11387168 target=_blank>Originally posted</a> by greenbean36191
We know now that this isn't exactly true. We don't see the constant, margin-wide upwelling on the western side of oceans, but now we know that upwelling of sub-thermocline water is frequent on western margins, including most reefs and probably plays an important role in nutrient influx. The difference is that on the western side of basins the upwellings are pulsed so the nutrients aren't available all the time to cause phyto blooms.

Regardless, I agree that phyto density is relatively low on reefs and the idea that phyto is the base of the food chain is erroneous. Primary producers are the base of the food chain, but that includes benthic algae too. Lots of animals feed on benthic algae as adults and then their larvae either don't feed at all in the plankton or feed on smaller zooplankton without phytoplankton ever entering into the equation.

I think it's also important to distinguish between feeding on phyto facultatively vs. constituatively, i.e. whether an animal needs to feed on phytoplankton or will eat it if it's available. Most of the critters in our tanks fall into the latter. You can give them more food and make them bloom, but beyond anecdotal reports that corals look healthier etc. I don't know of any great strong reason to believe those blooms are of any great benefit to our tanks.


Usually any animal that can swim against a 1 kt current isn't considered plankton. An animal that doesn't normally spend a significant portion of its life suspended in the water also usually isn't called plankton, so the benthic copepods, even if they do get swept up, aren't really plankton by most definitions.

I would be extremely surprised to find any significant amount of zooplankton in a reef tank unless you happened to sample right after a spawning event.

good stuff----then what inverts might one expect from a dedicated fuge for producing them---slow flow, cheato, rock rubble and deep sand bed.

 

[LobsterOfJustice]

Rosseau,

I cant really tell if you are agreeing or disagreeing . I agree with your information about the diversity of copepods and the fact that the term does not necessarily mean planktonic or benthic. That, in fact, is what much of my point is. The planktonic copepods eat planktonic algae; the benthic copepods eat benthic algae. The copepods we have in our tanks are benthic, so they do not eat planktonic algae (phytoplankton).

Everyone, I think what this all comes down to is misunderstanding of a few terms by the general community.

1. Plankton: Organisms which live in the water column and can not significantly propel themselves. Plant plankton is phytoplankton, animal plankton is zooplankton.

Most people call all the "bugs" etc they find in their tanks "zooplankton", but this isnt true. The stuff we find is our tanks lives on the rocks, glass, sand, algae, etc, not just floating around in the water.

2. Copepod: As Rosseau pointed out, any member of the order copepoda. Small crustaceans. They can be benthic (living on the substrate) or planktonic.

The ones we see in our tanks are benthic. They eat food that is benthic. There are copepods that eat phytoplankton, but they are not the ones we see in our tanks.

Am I beating a dead horse yet? :lol: Forgive me if I am.

I agree with bean's assessment of

I would be extremely surprised to find any significant amount of zooplankton in a reef tank unless you happened to sample right after a spawning event.

Capn,
A dedicated fuge can produce plenty of diversity and is still and interesting and beneficial part of a natural system. The main thing here is that we simply are not calling the critters it produces "zooplankton" because they don't float around in the water column. And because they dont live in the water column, they have plenty of food available other than phytoplankton. I'm not saying fuges aren't useful, and that healthy breeding pod and mysid populations aren't useful - I'm just saying they dont [need to] eat phytoplankton.

As far as specific stuff you can find, the big three I always think of are mysid shrimp, amphipods (usually in the form of gammarus shrimp) and copepods (tiny white moving dots). You will probably also get a lot of sandbed worm life, such as bristleworms, sphaghetti worms, and other little burrowing "things". You will probably see asterina stars, chitons, and stomatella snails on the glass. Mini feather dusters and spirorbid worms, vermetid snails, maybe even collonista snails, limpets... the list goes on. A lot of it depends on your particular rock... obviously this stuff can only show up in the tank if you introduce it. I didnt have collonista snails or limpets for the longest time, then I bought some frags from someone and a few weeks later noticed them at night in the tank.

 

[Aquarist007]

Lobster--thanks for your patience and dedication to explaining---as you have probably noticed have understanding of a lot of the parts and am trying to put it together for a more global understanding.
---having said that---and I no we have probably discussed it before somewhere------

I was running a filter sock for ages then removed it because I was lead to believe that is was being counter productive to the function of the fuge. In the light of what you said above I can't see that it is anymore.
The reason I am asking is that the berlin skimmer that I am running isn't the greatest and I think it was relying heavily on the filter bag----I have started to have trouble with cyano on the substrate in the main tank--and a form of red scum algae covering the cheato in the fuge. And a good deal of nuisance green aglae forming on the front glass even more then before.
None of my feeding or maintence habits have changed other then the filter sock has been removed.
I have a #3 korilia pointed right at the substrate so I know I am getting it up into the water column so it must not be filtered out by the skimmer.
I wondering if I should put the sock back on and crank the flow through the fuge for a couple of days to remove all that cyano/red aglae scum?

 

[LobsterOfJustice]

The point of the fuge is to get pods to the display. As long as the sock is not between the fuge and the display, it shouldnt be a problem. Most people have the sock right where the display drains into the sump, I can't see it being a problem there. FWIW, I run one about half the time. Whenever I feel like it, no real method to my sock madness .

Cyano seems to be much easier to prevent then get rid of. Basically you just have to increase the nutrient export. Siphon it out whenever you get a chance, and you're removing the nutrients with it.

 

[Aquarist007]

<a href=showthread.php?s=&postid=11394075#post11394075 target=_blank>Originally posted</a> by LobsterOfJustice
The point of the fuge is to get pods to the display. As long as the sock is not between the fuge and the display, it shouldnt be a problem. Most people have the sock right where the display drains into the sump, I can't see it being a problem there. FWIW, I run one about half the time. Whenever I feel like it, no real method to my sock madness .

Cyano seems to be much easier to prevent then get rid of. Basically you just have to increase the nutrient export. Siphon it out whenever you get a chance, and you're removing the nutrients with it.

thanks again---but howdo you increase the nutrient export in the refugium--crank up the flow, harvest more of the chaeto??

the chaeto ball has grown to the size of a 30 gal fuge and with it is a lot of trapped nutrients, detrius etc. I have harvested very little--only the dead stuff which hasn't been much.
It also might be time to stop the light being on 24/7 and go back to just nocturnally?

IMO--the problem in the main tank and the refug stems back to removing the filter sock??

 

[LobsterOfJustice]

I'm not sure how to increase export in a refugium... I dont have one.

On a side note, I've noticed you've been asking a lot of questions and making changes to your tank based on the answers. What it comes down to is everyone has different opinions. There comes a point where you have to listen to what everyone says, and then make your own decision. Some people use the socks, some people dont. If you have had good experiences with the sock, and had problems when you removed it, then who cares what other people's experiences in their tanks are? If you think that problem is removing the sock, then put it back on.

 

[Aquarist007]

<a href=showthread.php?s=&postid=11395797#post11395797 target=_blank>Originally posted</a> by LobsterOfJustice
I'm not sure how to increase export in a refugium... I dont have one.

On a side note, I've noticed you've been asking a lot of questions and making changes to your tank based on the answers. What it comes down to is everyone has different opinions. There comes a point where you have to listen to what everyone says, and then make your own decision. Some people use the socks, some people dont. If you have had good experiences with the sock, and had problems when you removed it, then who cares what other people's experiences in their tanks are? If you think that problem is removing the sock, then put it back on.

Thanks I hear you-----but trust me---I am very careful on who actually influences me to change---you can understand--the more you hang around here and are proactive the more you can tell the difference between pure anecdotal, experinced anecdotal, and this poster was born on the reefs with a tang in his mouth:lol: :rollface: :lol:

 

[LobsterOfJustice]

Cool. So did you stick that sock back on yet? :lol:

 

[Aquarist007]

<a href=showthread.php?s=&postid=11399900#post11399900 target=_blank>Originally posted</a> by LobsterOfJustice
Cool. So did you stick that sock back on yet? :lol:

of course

how do you feel about uv sterilizers effect on a copopod population--I removed mine six months ago--before I realized I am not really getting what I thought I was getting from the refugium

 

[LobsterOfJustice]

I dont know how I feel about UV. I have no experience with them. It's going to depend on the wattage, flow rate, and where you place it in the system (just like the sock). I guess overall, personally I dont think they really do much harm or good. Have you noticed any differences (good or bad) since removing it?

 

[Aquarist007]

<a href=showthread.php?s=&postid=11402602#post11402602 target=_blank>Originally posted</a> by LobsterOfJustice
I dont know how I feel about UV. I have no experience with them. It's going to depend on the wattage, flow rate, and where you place it in the system (just like the sock). I guess overall, personally I dont think they really do much harm or good. Have you noticed any differences (good or bad) since removing it?

more nuisance green algae on the glass ........ that's about all

its hard to judge because when I took it out I set up my fug, used the filter sock and starting running the duel reactors with phosban and carbon.
I was under the myth previously that it was nuking zooplankton---before talking to you and a couple of other guys

btw--I still intend to replace the filter sock with a mangroves and mud refugium at xmas

 

[Tu Ku]

: thinking that all of the things listed in this thread are either common or misconceptions

 

[Aquarist007]

<a href=showthread.php?s=&postid=11402679#post11402679 target=_blank>Originally posted</a> by Tu Ku
: thinking that all of the things listed in this thread are either common or misconceptions

that's good--everything listed is consistent with the thread title--
Common Misconceptions in the Hobby:lol: :rollface: :lol:

 

[LobsterOfJustice]

<a href=showthread.php?s=&postid=11402679#post11402679 target=_blank>Originally posted</a> by Tu Ku
: thinking that all of the things listed in this thread are either common or misconceptions

If you disagree with something, come on in and join the discussion! Tell us specifically what you have a problem with.

 

[Aquarist007]

<a href=showthread.php?s=&postid=11403112#post11403112 target=_blank>Originally posted</a> by LobsterOfJustice
If you disagree with something, come on in and join the discussion! Tell us specifically what you have a problem with.

:lol: :rollface: :lol:

I guess they were trolling along---er just passing through:lol:

 

[Tu Ku]

<a href=showthread.php?s=&postid=11403112#post11403112 target=_blank>Originally posted</a> by LobsterOfJustice
If you disagree with something, come on in and join the discussion! Tell us specifically what you have a problem with.

I don't KNOW that any of what's been said here is wrong. But that's just it, neither do any of the rest of us. We only know what someone has told us or what we've seen work in our own adventures. So it's a misconception to think that what's been said here is a common misconception.

Only someone with a "sure-shot, never-fail because I'm a marine biologist and understand everything about nature method" is in the position to actually dispell any misconceptions in my opinion.

All of the points stated in this thread are conditional and vary greatly based on the scenario that they're used in. With the occasioanl exception for hardware/drygoods.

I'm not in disbelief of this thread, and am an advocate of internet forums for just this reason. Thought/experience-pooling.

I know that not everyone will see eye-to-eye and we don't need a disclaimer at the beginning of every thread, but misconception is merely another way of saying "common things other people do that didn't work for me"

I don't mean to interrupt this threads momentum but you guys asked.

Actually my favorite misconception: the coral reefs are dying

 

[tydtran]

Explain to me how the "coral reefs are dying" is a misconception.