calcium...

emmelyn · Post by **emmelyn** » Sat Sep 22, 2007 1:51 pm

I'm currently getting ready to start my experiment on how different amounts of calcium will affect the bioluminescence of crystal jellyfish. I might switch the organisms to sea pens though. My question is if there is an affordable but quite accurate mechanism I can use to measure the amounts of calcium I have in the tank or put in the tank. Thanks so much!

Louise · Post by **Louise** » Sat Sep 22, 2007 2:23 pm

emmelyn wrote:I'm currently getting ready to start my experiment on how different amounts of calcium will affect the bioluminescence of crystal jellyfish. I might switch the organisms to sea pens though. My question is if there is an affordable but quite accurate mechanism I can use to measure the amounts of calcium I have in the tank or put in the tank. Thanks so much!

Two points:
1) make sure you have the appropriate authorization to work with jellyfish, most science fairs require additional paper work for projects with animals.

2) it is difficult to answer your requestion with out knowing how much calcium you need to measure and what "accurate" enough means. Do you need to measure parts per million, parts per billion, parts per trillion? Do you need to distinguish between 50 ppm and 5 ppm or do you need to distinguish between 5.1 ppm and 5.3 ppm? Also, many assays for ions aren't specific to one ion, so will you have other ions in the tank? (I'm guessing yes.) Let us know as much detail as you can and someone will try to help you out!

Louise

emmelyn · Post by **emmelyn** » Sun Sep 23, 2007 11:16 am

Thanks for answering so quickly! I did ask my teacher about authorization and it is only needed for vertebrates. Also, as for accuracy I'd only need to distinguish between 50 ppm and 5 ppm as I will be varying the levels in different kiersels.

Louise · Post by **Louise** » Sun Sep 23, 2007 11:49 am

emmelyn wrote:Thanks for answering so quickly! I did ask my teacher about authorization and it is only needed for vertebrates. Also, as for accuracy I'd only need to distinguish between 50 ppm and 5 ppm as I will be varying the levels in different kiersels.

I'm glad you've talked to your teacher about this issue. Just keep in mind that if you plan (hope?) to advance to higher level fairs, this could become a big issue. What are you going to do with the jelly fish when you are done?

I'm afraid I don't know what a "kiersel" is. Could you explain this? I was looking at information about salt water aquariums, and usually the calcium content is much higher (hundreds of ppm, since the ocean is at 400 ppm or so) than what you are proposing. Are you sure your values are correct?

Louise

adance · Post by **adance** » Fri Sep 28, 2007 9:30 am

I typed "measure calcium aquarium" into Google and got some useful hits, one inexpensive kit claimed to measure as low as 20 ppm. You might also try your local pet store that sells aquariums and fish.

Scronjsn11 · Post by **Scronjsn11** » Fri Sep 28, 2007 10:59 am

How long will these creatures live after you have tested them? If you move on to say State or National competitions...will the same ones still be alive? If not, your research will be biased because the original test group needs to be tested and not a second test group.

For example,

A study on worms cringing to light was once done. However no one can replicate the same results to this day. Your results must be the same from group to group, if in fact these creatures do not live to the next competition or test.

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