What determines PE..?? (w/ pics)

[Jester]

I always thought my Milli had good PE, but after looking back at some pics I feel differently... When I first brought the frag home about 3-4 months ago, it had great PE and now it seems to have barely any when comparing to the older pics... I check the tank at night and it has a lot of PE then... Here are a few pics showing the Milli when I first got it and a more recent pic from a week ago... any suggestions..?? Thanks in advance.

Jester

A pic from when I first bought the Milli... (mid Nov'07)
http://i79.photobucket.com/albums/j127/Jester4lfe/11292007/Milli.jpg

A recent pic... (Feb'08)
http://i79.photobucket.com/albums/j127/Jester4lfe/29gallon%20build/updates01312008/Picture187.jpg

[Kolognekoral]

Jester,

most corals only show polyp extension when they need to, that is to say, when they require food. It is not an expression of happiness or health, as often sighted. It is simply behavioural and some corals do it only at night (like a lot of people I know, but that's a different story :eek1: ). Mind you, no extension 24-7 is certainly not a good sign.

Looking at your milli frag, I get the feeling something is missing, though. It shows almost no growth in the 3 months you've had it. My first suspect would be high PO4. Over 0,08ppm and polyp extension suffers in most species. Best is around 0,02ppm, which is not always easy to reach. My second suspect is DOC (dissolved organic carbon), which may be present in too high a concentration due to inadequate skimming. Unfortunately, there is no test for DOC and it is only indirectly related to NO3 levels. Also, a third matter is water movement. Higher water circulation promotes better extension and better health in general. Most aquariums I've seen have too little current. Too much is rarely the case. The importance of the current is the gas exchange at the coral tissues surface. This is, also, part of the PE behaviour; waste product exchange.

Hope this helps, a bit.

[Jester]

<a href=showthread.php?s=&postid=11786459#post11786459 target=_blank>Originally posted</a> by Kolognekoral
Jester,

most corals only show polyp extension when they need to, that is to say, when they require food. It is not an expression of happiness or health, as often sighted. It is simply behavioural and some corals do it only at night (like a lot of people I know, but that's a different story :eek1: ). Mind you, no extension 24-7 is certainly not a good sign.

Looking at your milli frag, I get the feeling something is missing, though. It shows almost no growth in the 3 months you've had it. My first suspect would be high PO4. Over 0,08ppm and polyp extension suffers in most species. Best is around 0,02ppm, which is not always easy to reach. My second suspect is DOC (dissolved organic carbon), which may be present in too high a concentration due to inadequate skimming. Unfortunately, there is no test for DOC and it is only indirectly related to NO3 levels. Also, a third matter is water movement. Higher water circulation promotes better extension and better health in general. Most aquariums I've seen have too little current. Too much is rarely the case. The importance of the current is the gas exchange at the coral tissues surface. This is, also, part of the PE behaviour; waste product exchange.

Hope this helps, a bit.

Thank you for that detailed response. I will test my parameters tonight and post them here. I need a PO4 test kit, so off to the reef store I go...

This has happened with a few frags I have... in the store that look "hairy" with PE and then once I get them home, the PE is gone... Maybe they are jsut really hungry at the store..?!?! =)

[Kolognekoral]

Jester, a tip on PO4 test kits. The best are from Rowa/Merck. A bit more expensive, but they test well behind the zero, which most do not. As I am in Europe, I am unware what other brands you may find, but check the testing grade before buying!

[TheCommersoni]

In my experiences with milles go, flow has the biggest effect on polyps extension. If you can move to an area with higher and more chaotic flow, the polyps will start to come out more. Becareful though if the flow is too direct or too strong it can blow off tissue. And I also wouldn't worry about polyp extension until the colony grow to the size of your hand. Thats when you can really tell.
<img src="http://i34.photobucket.com/albums/d117/C_Cobb/22.jpg" height="400">

[BradR]

<a href=showthread.php?s=&postid=11786640#post11786640 target=_blank>Originally posted</a> by Kolognekoral
Jester, a tip on PO4 test kits. The best are from Rowa/Merck. A bit more expensive, but they test well behind the zero, which most do not. As I am in Europe, I am unware what other brands you may find, but check the testing grade before buying!

Ouch, 85 bucks for a test kit. Oh well, anything for the corals...

[mjstover]

What is PO4?? Sorry might be a dumb Question

[Kolognekoral]

PO4 is the chemical we refer to as phosphate. There are various forms of phosphates in aquariums, but we are only able to test for one (with our test kits, in any case). Check out this article to get a good basic understanding.

http://reefkeeping.com/issues/2006-09/rhf/index.php

[stony_corals]

PE isn't just a feeding response, it's a gas exchange response, exposing more surface area for more O2/CO2, or too much. Never use PE as an indicator of health like Jamie said...

[Jester]

I jsut can't figure out why they PE would be so much different at the store than it would be in my tank... i went up there and talked about it a little with him this afternoon and the only think he could suggest was that my skimmer wasnt skimming enough... hmmmm...

[Kolognekoral]

Good skimming is important, as it removes DOCs (dissolved organic carbon) as well as many other organics. The current thinking is to lean toward over skimming, rather than too little. One is constantly adding carbon sources through food, so its continual removal is of no real consequence, but its build-up has been linked to RTN and other coral diseases in the wild.

Have you checked the PO4?

[Jester]

I was not able to pick up a PO4 test kit... the ones there were the cheap ones that didnt seem like they would do the job after checking for what you said above... I'm probably going to order one online... I also need a good Mg test kit too... I think I have all the test kits besides those two...

[j.prostrata]

Jester, if you have a local club see if anyone has a hanna meter and would do a test for you.

[Obi-dad]

IME lower flow and presence of certain types of fish caused less PE. What fish do you have in the tank?

Pygmy angels, clown gobies and others can cause low PE. I had a flameback angel that nipped enough to cause it, then they went back to normal after I removed him. Same for a clown goby I had later.

Just recently I upped the flow in my tank and had more PE then next day.

[twon8]

<a href=showthread.php?s=&postid=11789351#post11789351 target=_blank>Originally posted</a> by Obi-dad
IME lower flow and presence of certain types of fish caused less PE. What fish do you have in the tank?

Pygmy angels, clown gobies and others can cause low PE. I had a flameback angel that nipped enough to cause it, then they went back to normal after I removed him. Same for a clown goby I had later.

Just recently I upped the flow in my tank and had more PE then next day.

agreed, even though you may never see them nip, any pygmy angel is likely nipping and causing poor daytime pe.

if the op's signature info is correct he has enough flow.

[foltzcd]

I have mandy colonies of milies and acros in my main tank (160g)and frags of the same in my frag tank (30g). The frags have great polyp extention in the frag tank but little in the main tank. The frag tank feeds off the main display so the water is exactly the same. The main differences between the two include:

1) One Tunze pump in the frag tank with circular current vs. 2 Tunze pumps in the main with variable current on a multi-controller and two return lines on SQWIDs alternating to 4 returns. The main tank gets a lot of variable current.

2) Frag tank lighting is one 175w MH while the main display uses a Solaris and VHO supplements.

3) The frag is fishless while the main has several fish including a few pigmy angels (although I have never seen any fish pick at any of the live coral).

Any ideas why the difference?

[moo0o]

like twon8 and obi-dad said..probably number 3. i know my bi color angel nips at mine every once in awhile...i want to remove it...but that fish is too smart =(

[Brewen]

Jester I know in mine it was clown gobies in my tank that caused lack of PE and even a few deaths of sps. I did not see a fish list? All I can say is I had to tear my whole tank down and apart to get the fish out, best of luck mooOo

[nava405]

well, i have problem with TOO MUCH PE, any location wether low / high flow and i hate it...

[midas blenny]

<a href=showthread.php?s=&postid=11790334#post11790334 target=_blank>Originally posted</a> by nava405
well, i have problem with TOO MUCH PE, any location wether low / high flow and i hate it...

lower flow a little. and watch what happens

[-=Efrain=-]

I had no problems with PE until I added a Flame Angel and now during the day light hours my PE is no where near what it use to be. The flame does pick at the corals. So I am looking into building a trap. Its almost like corals have a type of memory to were if it gets picked on it will not extend its polyps until lights out. I would like to know who out there feeds Rods every day and still gets great PE just to disprove the hunger theory..

[danikowa]

but, does PE effect the growth of the coral, or is it merely asthetic
??

-Dan

[moo0o]

i feed rods everything and i still get great PE during the night =) however, when i feed rods....there is no PE..because its during the day and i have a bi color angel

[moo0o]

<a href=showthread.php?s=&postid=11793297#post11793297 target=_blank>Originally posted</a> by danikowa
but, does PE effect the growth of the coral, or is it merely asthetic
??

-Dan

good question, id like to know too.




everyday**

[Kolognekoral]

Polyp extension is related to growth, but indirectly. A coral that doesn't show any PE is not growing much, if at all. The reason is, it is not properly respirating. One can think of PE as an type of breathing and eating in one. When the polyps are fully extended, the coral is having its largest surface area, thus has a higher rate of respiration. It, also, uses the extended polyps to capture prey AND absorb nutrients direct from the water column.

Apparently corals can respirate over their entire tissue surface and must not extent their polyps for this function. This is an additional apparatus to raise the rate of respiration. Extension during the evening hours makes sense as this is when currents are a bit slower (extension compensates for less water movement), particulate food is most abundant, predators are sleeping and the zooxanthellae in the coral can give off their CO2 more efficiently. Remember, a coral is a symbiosis of plant and animal, both of which have dissimilar breathing methods. Animals need O2, which the algae produce during the day, while at night algaes produce CO2, which needs to be dispersed out of the tissues. (essentially, this is what respiration is!)

Corals that show PE only at night are following their natural pattern. Only a handful of corals open their polyps during daylight. Some corals (typical of table forms) only open innerer polyps during the day.

Now, the question of why corals may extend 24-7 in the aquarium, when that would not be the case on the reef, leaves one to believe something is not right. To be honest, I'm really not sure what it means. It could be that the coral is growing a such an excellerated rate that it requires extra respiration time. It could mean that the coral doesn't sense any predators and has taken advantage of this to increase respiration. It could be that the corals are hungrier in the aquarium and need more feeding time to cover the deficit. Don't forget, we keep our aquariums much cleaner than the reefs. Most reefs have periods of high turbidity, which feeds all the organisms. Our aquariums are pretty pristine at all times; no plankton bloom, no periodic heavy current and wave action to stir things up, consistent lighting, etc.

What ever reason the corals have, we can't connect PE to good health directly. It is simply an indicator of the corals metabolism. If a higher metabolism is better is disputable. It may accelerate growth, but at the cost of a densely deposited skeleton or a weaker immune system. Organisms have an evolved over generations metabolism. I doubt we need to worry too much one way or the other, but PE is a nice indicator that the coral is at least carrying on its life processes. We simply shouldn't be tempted to use it as the sole indicator of good health. It is very misleading. After all, a stressed and dying tree will spurt into growth in a last hurrah, just before it kicks for good!

[kb27973]

<a href=showthread.php?s=&postid=11789857#post11789857 target=_blank>Originally posted</a> by Brewen
Jester I know in mine it was clown gobies in my tank that caused lack of PE and even a few deaths of sps. I did not see a fish list? All I can say is I had to tear my whole tank down and apart to get the fish out, best of luck mooOo

Amen to that. I had exactly the same experience with two clown gobies. Acro frag deaths and NO polyp extension on any acro. I also had to tear up my tank to get them out. If you have acros these are very bad fish to have.

Ken

[Kolognekoral]

Can you give me the latin name? I'm unfamiliar with 'clown gobies' and a lot of them could carry this name in my mind. I definitely want to make a note of this.

[Brewen]

Gobiodon citrinus

[Jester]

<a href=showthread.php?s=&postid=11789857#post11789857 target=_blank>Originally posted</a> by Brewen
Jester I know in mine it was clown gobies in my tank that caused lack of PE and even a few deaths of sps. I did not see a fish list? All I can say is I had to tear my whole tank down and apart to get the fish out, best of luck mooOo

For my fish... I have two black and white clowns, one blue and yellow damsel, and added a lizard goby a day ago... hopefully all gobies arent like the clown gobies you were all talking about...

I got my skimmer running really wet now, so maybe that will help a little...

[Kolognekoral]

I had Gobiodon citrinus a few years back and had no problems. Maybe the source reef has something to do with it. Many fish from particular areas have different diets from the same species on another reef. An example is Chaetodontids from the Marshall Islands. They show a much higher rate of coral consumption from the same species on other reefs. Marshall Island C. aurigas will decimate a reef tank, while those from Indonesia show no interest. This was based on actual wild specimens diagnosed for stomach content.

[kb27973]

Gobiodon okinawae are the ones I had. All they do all day long is go from one coral to the next rubbing all over it. I think they may be okay in large colonies but frags they will kill. I know, I lost a Red mille, Yellow mille and many other acros are still recovering from the constant rubbing. They seem especially fond of millepora.

Ken

[Badgerman]

The problem here, I think, is too little nutrients. With an aquaeuro 135 in that tank, you're gonna need to feed heavily or get more fish to have more food for the corals. This would also darken up your colors a bit.

[Jester]

Lately the PE has gone back to how it was originally... I found out I had really low Mag, too... not sure if that caused any of the low PE, but now things are looking great and the Milli seems to have really taken off growing now...

[Jester]

**Double Post**

[Kolognekoral]

Jester, good show! Mg is related to skeleton deposition, as it needs to be in a certain ration to the calcium to allow for efficiency. This may have been the missing link. Ideally one should mimic NSW (natural sea water), which has a Mg of about 1200mgl and Ca of 420mgl.

wishing the best success,

[Jester]

<a href=showthread.php?s=&postid=12053686#post12053686 target=_blank>Originally posted</a> by Kolognekoral
Jester, good show! Mg is related to skeleton deposition, as it needs to be in a certain ration to the calcium to allow for efficiency. This may have been the missing link. Ideally one should mimic NSW (natural sea water), which has a Mg of about 1200mgl and Ca of 420mgl.

wishing the best success,

I was definitely somewhere near 950 on the Mag... my Acros were not looking happy either, but now things are looking to be turning around... Thanks again everyone for there suggestions...