corcea clam bleaching slowly, help

[danlu_gt]

I have 4 clams, two of them are corcea clams. I have them for over 3 years now. However, recently one of my corcea clam is bleaching slowly for 3+ months now. What can be the cause? I haven't change the metal halide bulbs yet nor did I lower the distance to the water level. The other corcea clam looks fine and is sitting right next to it. The bleached corcea clam still opens fine during the day and will still react to shadows. From looking at the new shell growth, it's growth is a bit slower now comparing to the healthy corcea.

I'll take picture soon.

 

[danlu_gt]

Here's the picture. The corcea on the left is bleaching.

http://www.reefs.org/phpBB2/files/img_3397_171.jpg

 

[mbbuna]

try moving them up into the rockwork closer to the lights,what lighting are you using?when was the last time you changed your bulbs? what size tank?how far are the clams from the lights

 

[Electrobes]

How old are the bulbs? It kinda looks like UV burning.

Also it could be "dirty" water. You have to understand that I am trying to figure out as much as I can by the pic, and I see a SPS colony with hair algae and receding. I don't see any cyano which is why I am thinking it might be UV burning...

What color spectrum are the bulbs and how long have you've been running them (including your actinics, if you have any).

 

[Herbert T. Kornfeld]

Clams can UV burn....naaaaah, you gotta be kidding me. My croceas love being right under the biggest halide I can get them.

 

[danlu_gt]

My clams are under 2 250W Iwasaki 6500K bulbs plus 2 110W Actinic 03 VHO. Take is 2ft deep and the bulbs are ~6"-8" above the water. 2 of my sps colonies had RTN last month. The bulbs are just 14month old. I just order replacements last week. The the UV amount change increase as the bulb age? About 3 months ago, I added ozone with ORP controller, which helps clear the water (same effect as active carbon as for as water clearity). I just added 7 Lyratail Anthias, but they were too big for my quaratine (25gal) tank so I just put them in. From what I can tell, none of my fishes bother the clams. I just cleaned its shell yesterday and didn't see any thing unusual.

 

[mbbuna]

ozone is a lot more powerful at clearing water then GAC.im guessing that your running your ozone thru ur skimmer?are you running the skimmer efluent thru carbon?if not then start you dont want free ozone in your tank.what do you have your ORP set at?you dont want it over 400,350to 375 is just about right.

 

[Electrobes]

wait the bulbs are 14 motnhs old???Yes UV burning increases when bulbs get older.

I use a 250 watt Iwasaki 6.5K with T5 actinics, and even though they say Iwasaki's can last a lot longer I still plan on hvaing it replaced maximum once a year. The color spectrum on a 6.5K bulb goes only towards the red side, which leaves very little spectrum room as the bulb loses its spetcrum.

Not only do I think the old bulbs caused your clams and possibly the other corals UV burn but the using of ozone increased it. Though I am not necessarily suggesting that it could have been over done or what not, but clearer waters only helps the UV burning. I would definitely replace those bulbs... by the way I love your choice of bulbs.. these Iwasaki's are great!

 

[Herbert T. Kornfeld]

Let me put this into perspective. Crocea clams in the wild often grow in coral heads that extend above the normal water level during low-tide. This 'lagoon' gets heated well above 100, and has about 6" of water actaully covering the clam. All this happens even just off the coast of australia where the ozone layer is thinner than elsewhere in the world. Thats intense. I have seen clam grow-out tanks only 6" deep with 1000watt 6500K bulbs a few feet above. UV burn a crocea? You gotta be kidding me...they are perhaps the most UV resiliant organism on the planet. Those pretty colors you see in the mantle are in fact the pigments used to reflect a large portion of the UV they encounter. The more you try to burn them the prettier they get. Unless you took a bleaching one and gave it too much light (making it more vulnerable to UV w/o its pigments)...you gotta be kidding me. Croceas bleaching due to topo much light? Too much UV? I dont believe it. Did you know that in the farms where they raise them they dump barrels of pure ammonia into the water for fertilizer...they suck it right up. I would bet that some sort of water parameter is off...calcium, alk, etc...before thinking that you are giving it too much light. They are light whores.

 

[Drewpy]

They are light whores. [/B]

Light Whores... lol

 

[mbbuna]

im not and have never suggested UV burn, but what I am suggesting is an acclamation to the cleaner water due to the ozone.even if the 6500k bulbs have shifted(I don't think this is the problem)they wouldn't be dumping UV. if they were 14-20k and 14 months old then it may be a problem. I would agree that croceas are light whore's, but to state that uv would have no effect on them!your off your rocker I would suggest shading him(them) for a few weeks

 

[Herbert T. Kornfeld]

All that coloration that they have is not their photosynthetic algae cells...its their UV protection...the more colorful and glowing they look, the better their protection. Look how quick a person gets sunburn in the tropics, and then think about how long that person would have to be under a halide to get the same...a long time. People go to tanning beds for more controlled (read: less intense) exposure to UV over risking the randomness of the sun. I have seen people growing clams under DE bulbs w/o the glass shield...thats gotta be worse. They could be considered the most UV resistant organism on the planet. Scientists are studying them for clues into how to prevent skin cancer. Anything just short of running a UV sterilizer bulb over them would be nothing more than a dent in their armor. Its gotta be something in the water. How are your phosphates? Mg? Nitrates? Temp? Silicates? Organics?

 

[mbbuna]

I NEVER SAID THAT THIS WAS UV BURN! but are you telling me that they cant be UV burned? IF that's what your saying then your are off your rocker!!!!any photosynthetic organism needs an acclamation period.ozone is very powerful,and if someone just starts using it it can cause havoc . and I've NEVER heard of ANYONE dumping barrels of pure ammonia in to clam grow out tanks.Herbert you are way off base here!

 

[Herbert T. Kornfeld]

"and I've NEVER heard of ANYONE dumping barrels of pure ammonia in to clam grow out tanks.Herbert you are way off base here!"

The farmers in the pacific raise the clams in shallow beds and yes, they dump 55gallon drums of pure ammonia into the beds as food for the clams...they suck it right up.

I wasnt talking to you exactly about the UV burn...no need to get excited. Im with you on the O3...esp if the O3 is bleeding into the tank...but then other things would be showing bad signs as well.

I had a freaky crocea clam death as well. It was one where the shell was growing slower than the others as well. Shortly after moving it to a new tank while attached to a large rock, it started leaning off the rock. Then it was hanging off the rock by its thread. So one day, I thought I would be nice and pick up the clam, and reposition it on the rock. It freaked out...It looked like the clam had a heart-attack or stroke...it quivered, and retracted deep into its shell...ripping parts of its mantle away from the shell. It seemed to be alive for a few more days, although having seperated from its shell. One day I woke up to see a hermit going to town on it.

So for no good reason at all, the crocea killed itself. Ill never understand why. That growth thing has me wondering though. Cuz this one did look like its mantle was getting huge, yet its shell wasnt gaining rings like the others. You think its possible your calcium levels/alk are off? Maybe the organism is outgrowing its shell and making it vulnerable...in my case to a quick death, in your case: a slow one.

 

[Electrobes]

With this being a forum, there are many opinions and I believe that none should be flamed unless it obvious that it should be So let me counter your attack on my post:

When speaking of the crocea's incredible abilities at UV protection and what not you can imagine the same going for acroporas and other stonies which get left out of the water for hours at a time with a low tide about. Sure they, like clams, can withstand a hell of a beating and be fine. Technology tries to mimic the sun but obviously we can't.. and I think you aren't seeing my own point of this idea: The older bulbs are increasing in UV emittance.. and your defense I believe lies in Intensity, not malfunction. I did not believe the intensity of the bulb was causing the UV burn, just the age of the bulb possibly losing its spectrum causing the UV to be a lot higher than normal.. which would also account for the excess algae in his tank based on the photo. Also in his specific situation he is using a 6.5K bulb. Unlike the other types (10K and 20K) if the 6.5K loses any more spectrum than it was originally at then the chances of the bad spectrum being present is even more a possibility. With the people who use the other types of bulbs, they have more time to take care of the situation as the bad spectrum will not be reach for a longer period of time.

Anyway, I never intended to make you guys believe that UV burning was the only cause.. more like an effect. I think that something is definitely stressing the coral/clam to become MORE vunerable to the UV emittance, could be water quality which I mentioned, and it definitely could be the excess Ozone that may be in your tank, allowing the UV rays to reach farther down.


Even if the other clams are fine, it may be that they are more hardy than the one that is hurting. In time all of the corals would die if the bulb really is losing its spectrum and dishing out UV rays. This would do a number of things not just a single attack... the algaes would proliferate the tank choking the other inhabitants of the aquarium. And think of this also.. if you decide to replace the bulb be careful of the timing.. because if you corals and clams are a bit weak, and have not been receiving the same intensity as usual, you may stress them even more with a brand spanking new light.

I comepletely forgot to mention this... if the light is old your coral may be bleaching for lack of light. As the bulb ages it is estimated that about a 25% drop in intensity occurs.. I think per month extra the bulb is running.

 

[Electrobes]

Oh and about the dumping of pure ammonia into the clam beds,, you are both right/wrong. It (Its not exactly ammonia, I forgot what it is) is dripped into the clam beds and they do consume it to a point. It is not as simple as it looks... but it is doable in a large breeding facility.

The freaky crocea death... did you look for any signs of paratism?Maybe it had an air bubble stuck in it which causes clam "freak-outs" but you possibly didn't see it when you took it out and back in during the tank move?

 

[Herbert T. Kornfeld]

With regards to the corals that are exposed to sunlight...they do tend to die off at this stage, and the clams dont...suggesting the clams have a much higher tolerance than the corals. And being that most of the corals in the home reef prolly arent the light-hungry surface-breakers in the wild....makes me come to the conclusion that if it were UV, you would see dead corals long before the crocea would be hurt.

 

[mbbuna]

in the hatchery the water is artificially fertilized with nitrates and phosphates to enhance growth.it is dosed it to the system to keep the levels constante.nitrates are a little deferent then pure ammonia.if they were to dump a 55g drum of pure ammonia it to a grow out tank it would kill the clams,unless the tank was like 1/2 a million gallons

 

[Electrobes]

Where did you read that they died of in that "stage"?.. the SPS I mentioned do not die Herbert, they are exposed to the air for a couple of hours and then get re-submerged again after the tide comes back in and live life as usual. Clams actually do not get exposed to air but they do break the water surface. Most of the clams found in the wild are embbeded into rocks (croceas and maximas) that they have bored into. When the tide becomes very low the water inside the bored-into space stays there with the clam, while the other SPS colonies that break the water surface are literally hung out to dry. It does however, as you mentioned, get very hot in the spot they are in and they are also getting beemed with light like the others... but they are not in the same situation as the SPS colonies I have mentioned.

The more important point I was trying to make was that it is not the intensity that may be damaging the coral... the situation you keep posing for me has to do with intensity. If you were to take any tank with metal halide lighting, and removed the UV-glass shield for even a day.. be it the SE or the DE you would see massive death, be it a clam, SPS or anything else.


When I worked at a LFS I have seen a number of tanks in the situation as this: Their SE halide (biggest seller here) breaks, the outer glass cracks. They decide that instead of leaving the dangling outer glass piece there, they take it off. They would call the LFS on average about 5-8 hours later wondering why half (for those who had two halides, which is what most people here have) of their tank is completely sloughed off and dead. And yes.. these death tolls include clams (especially maximas and croceas as they are the bigger sellers in this area).

Again I want to stress that its a technological malfunction that typically results in a long-term clam dying of all of the sudden. Other typicals include paratism, which I don't believe to be it because it usually causes the others to follow suit rather quickly. It could definately be a water quality issue as its the number one cause of inhabitant problems in reef tanks.

I tend to think that water quality problems (be it excess ozone, under filtered water, etc) is the cause of the effects later seen by aquarists. If you think about what I just said (an excess of ozone) thats a technological malfunction.. just thought that was funny.

 

[danlu_gt]

Thanks for all of you guys' suggestions. I run the ozone around 325-350mv with the ORP controller. My Ca/Alk fluctuates because I'm using 2 part Ca, but don't test/dose regularly. I have done this for almost 2 years and clams/coral has grown a lot faster with the 2 part Ca. I understand the light intensity drops with aging bulb, but didn't realize about UV increasing. I purchased a UV card to detect level of UV and I'll compare with the new bulbs when they come in. I always thought UV drops with aging bulbs because in the past, I change the Iwasaki every 2 years and corals seem to do better when the bulbs are aged after 6months. Maybe they were stocked by the inital intensity of the new bulbs.

Back to the ozone issue.. I do run active carbon, but not as much as before I started using ozone. Ozone is injected into the skimmer, but the carbon are run in a close loop cansister filter. Interesting note... I have a 25gal quarantine tank, which I drop a few corals that RTN. I dose ozone to low 600mv for 2hrs to see if it'll kill whatever that's causing the RTN. Well, polyps that haven't RTN closed up, worms and pods either buried in the sandbed or float to the top (but still alive), flat worms seems not to be effected. Anyway, affter ORP drops back down, coral polyps open back up but some RTN still continues. From what I read in the past, I thought such high ozone would kill everything instantly. Probably will kill everything if it's over 24hr period. So my questions is that running ozone in the skimmer, is that enough ozone contact time to kill bacterials and floating parasites? Has anyone run ozone at normal levels with ich filled tank?

As for my bleaching clam.. I'll switch to the new bulbs and see what happens. Since I just added 7 Lyratail Anthias 4 days ago, I'll wait a few more days before I turn off the ozone for a week.