Kalk: We have discussed heavy metals before and I posted the results I got from AWT plus tried using the pads that supposedly turn color for certain impurities. I am currently working with Hanna on a new product release (well trying to get them to increase the range of a couple tests) that would give me much better insight into heavy metals as well as all the regular stuff we test. Unfortunately, there is just no way for me to know right now.
There IS a gold ring in the tank somewhere, but I doubt that coud be the problem since it has been in there since '06. My kalk has been giving me problems of late so perhaps that is an area of investigation. It has been becoming "weak" much too quickly and leaving a brown residue in the reactor.
Regarding salt: I test for everything I can somewhat religiously. Way more than the average reef keeper for sure. That doesn't mean there is no lead in it though.
Regarding additives: calcium bones soaked in RO/DI for days, swapping out until there is no PO4 leaching; Carbon soaked in RO/DI for days until completely devoid of dust, PO4 etc. Baking soda right out of the bag; kalk right out of the bag.
And that's it.
jmaneyapanda: I doubt it's the lighting. They have been under the same lamps for two years and the problem only came up in the Winter.
skinz78: I have had a couple of corals go over the last month. I had one pillar type coral rot from the inside out. I noticed a small amount of STN on the underside while fishing clams out of the tank, so a couple days later I pulled it and broke it off. Inside the "pillar" was the most foul black sludge, smelling like concentrated dead snails. About 90% went in the trash.
I also lost both duncan colonies.
The fact that the clam in QT is bad suggests only one common denominator: salt.
johnnybravo234: They WERE nice teardrops.
I am still very suspicious of alkalinity in this case. Although I have been able to maintain 7.0 - 8.0 for the last few months based on previous discussions and my own set point of 9.0, I feel that this parameter has been too unstable.
Seems strange that so many reef keepers in the Seattle area have lost all their clams though.
And one more interesting note:
I was perusing the latest "Aquarium Fish" and found a blurb about diseased clams. Unfortunately a google search brings up only 4 useless entries so I will write the blurb below:
IMPORTED DISEASED CLAMS DISCOVERED
Giant clams know as tridacnids that were imported from Vietnam were discovered to have Perkinsus olensi, an internationally reported pathogen. A University of Florida veterinary pathologist made the discovery, which is not believed to be a threat to human health or other reef species.
However, the pathogen's presence concerns scientists and aquaculture industry representatives. Giant clams are an increasingly large proportion of the live invertebrates imported with the intention of becoming aquarium specimens.....
Not to infer that my clams died of this disease, but I do find that interesting, especially since they all died at the same time. Also we in the Northwest are probably getting the majority of our clams through the same import source.
