Reefing “A small coral growth system for the classroom"
Hey guys,
Sorry to have been such a no-show on DB lately. Teaching 7th and 8th grade science has taken All of my free time.
I’m currently in the process of designing a SMALL system to grow coral in the classroom. The purpose here is to demonstrate light dependant growth differential in Caulastrea sp. and Montipora digitata.
At this point I’m thinking of using a 48” wire rack shelving unit (covered with plastic sheeting to protect against corrosion), a 10, 15 or 20 gallon long tank, and a Hagen 200 gph hang on the back type overflow filter (for circulation and phosphate removal). I have a 2 X 65 Watt PC fixture, which I intend to use for lighting. This tank will be simple. No protein skimmer, sump, or any other gadgetry. Live rock will be minimal (perhaps just a pile of lave rock under the eggcrate that will be used to support the corals). Aside from the corals I may have a small red sea fish and a cleaner shrimp. I work in a Jewish day school so a red sea connection would be good.
This is intended to be a long-term lab. The 7th grade (biology) will be concentrating on photosynthesis, respiration and classification (as in, what is a Cnidarian, and what is an Anthazoan). The 8th grade (Chemistry) will be concentrating on the photosynthetic equation, The respiration equation, and calcium carbonate deposition. Each grade will weigh and photograph their specimens at the beginning of the lab (sometime soon) and again in the end of May. The students will chart growth differential between corals grown near the surface and corals grown at greater depth. In addition the chemistry students will calculate the amount of calcium, carbon and oxygen that makes up the newly deposited skeleton (of course there will be some error in this calculation due to water weight in the coral tissue but this should be minimal and is of little concern at the seventh and eighth grade level)
What I would like, is for you guys to comment on my idea. I’m an experienced reefer and I’ve been working with both of the corals mentioned above for at least five years. I’ve grown both under the light source mentioned above as well.
Good stuff Chris. Our local club on Long Island does something similar, we donate tanks to schools on the island and then have the teachers use it in their program. Montipora sp. will be a great example to show what you've outlined. Aside from growth rates, changes in color due to light intensity will also be apparent to show the points you are trying to make, and it also has the more visible 'skeleton' since it's a small polyped stony (which will help show the growth and use of calcium).
I'm not sure if this deviates from what you have planned but are you also going to have them test for dKH along with calcium so they can see how alkalinty and calcium levels in the water are related?
I’ve thought about doing some water testing with the kids, but understanding the concept of alkalinity is probably a bit out of their league. Remember that these are your standard 8th graders. A limited number of them are interested in the living world. Mostly they are interested girls/boys, cloths, music, sports, etc. I tend to teach above the curriculum anyway. I have to continuously remind my self that they are only middle school kids.
I will do specific gravity and pH, but that may be the extent of it. If the lab works well and the seventh graders really get into it, I may allow one or two of them to do a science fair project involving water chemistry and coral growth next year. For now I want to keep things fairly simple.
The biggest problem that I have the limited amount of water that I can use. This is not because of space but because of the fear of a leak or broken tank. I haven’t been at this school long enough to dump 75 gallons of saltwater on the floor (I’m on the second floor)
I’m thinking that a 15 or a 20 long will probably be as large as I will go this year.
The smaller tank shouldn't be a problem since it sounds like you know what you're doing, although without a skimmer or other form of nutrient export weekly water changes would definitely be beneficial. In my high school marine biology class our teacher had us take turns doing this every Friday and it worked out well.
Another idea, though it might get in the way of the coral, would be to grow various algaes in there and show how the ecosystem works - with the plants using the nitrates and phosphates to grow. While the growth rate of Caulerpa would be nice to show this it would definitely take over the coral and ruin the other experiment. I don't want to generalize but the jewish schools in my area usually lack in the science department as far as 'hands-on' stuff goes, and I do think a portion of the students will really appreciate what you're doing for them.
I think I may also have an extra canister filter around I can donate if you have a use for it!
Your plan sounds good to me, Chris (most of my reefkeeping experience has been with nano systems).
I would recommend going with a baretbottom setup to prevent the substrate from becoming a nutrient sink/sponge and easier to just suck the detritus straight out of the tank to more easily maintain water quality (sooner you can siphon it from the tank, the less time it has to break down into ammonia, etc.).
As far as a Red Sea fish, I would recommend a 6-line wrasse: nice and small, colorful and quirky. Being a reflection of the Red Sea, I would have a hard time not throwing some xenia in there...!
Grassypeak: I'm curious if you will take any steps to guard this from vandalism? I know that at our highschool a saltwater take in a chemistry class was done in by some kids pouring in some HCL(I guess they wanted to see salt precipitate out of solution...). It now sits empty and even though I've prodded a few people nobody seems interested in trying again yet.
While it is a very tiny risk, if the moral of the class is low(or extremely high
:lol: ) someone could get a dumb idea. The 8th grade biology class I was in was an absolute nutcase but I'm betting you're a much better teacher than the many we had.
Michael,
Thanks for the ideas and the offer for a canister filter. I’m fine in the equipment department despite the fact that I’ll be funding this project on my own (I’ve already spent whatever the school had allotted to my room).
The Caulerpa is a good idea but the refugium/bug tank will have to wait until next year I think.
Sky,
Will a sixline be O.K. without a sand bed? I was thinking about a Fridmani, but I’m not sure if they can coexist with a cleaner shrimp or not. I’ve never kept a pseudochromis or a sixline wrasse.
Dendrobait,
There is always the chance that some bozo sticks something in the tank but these kids are a little less destructive and a little more morally conscious than most. We do kitchen chemistry for the most part, so It would be difficult for them to do anything with chemicals. I have 1 molar HCl, but even that is locked up. It would be more likely to find some random object (a penny, god forbid) in the tank than anything else.
A 6-line will be fine without a substrate (have personally kept them without). They sleep within the rockwork, finding some small nook or cranny and then enveloping themselves within a bubble of mucus. I've never had a problem with them and cleaner shrimp together.
Reefing “A small coral growth system for the classroom"
Linear Mode
