Science Fair Project

[mcdonaldjosh7]

Hey,

So i am doing my science fair project on how the lower salinity affects coral growth. I have four months to test it, so I would like to know a couple of things:

a) what type of corals grow fastest?
b) what would be the most cost efficient way to set this up? My thinking was 3 ten gallons with HOB filters. I would then need to know what type of lights I would need...Because I would rather use one light fixture to light all three than three different light fixtures.
c) what type of filter is the best that is:
1)HOB
2)cheap, but will still work well enough to keep corals alive. Basically they dont need to by long term, just well enough to last four months.

The reason for doing this is to show what is happening with global warming and how it could affect corals. Basically the polar ice caps are melting which means lower salinity levels in the oceans.

 

[akunochi]

First....Lower salinity levels because of melting polar ice caps????Really....but I'll bite.

I would say Zoas grow fast.

HOB filter???iunno an aquaclear maybe.

 

[mcdonaldjosh7]

well i have to have 3 separate filters because i cant have the tanks cross contaminating.

and yes, as the polar ice caps melt, more freshwater is dumped into the ocean. therefore, it dilutes the salinity in the water.

 

[ATP123]

a) Probably the xenia is the most cheapest and fastest that I've had experience with
b) Maybe a Rubbermaid with an acrylic sheet separating it in half and a power head with maybe PC's for both of them.
c) what type of filter is the best that is
1)HOB
2)probably you could put some LR and some macro algae in the Rubbermaid to keep nitrates low.

 

[mcdonaldjosh7]

for a)

would xenia require the lighting that a lot of sps and lps require?

 

[returnofsid]

LOL You'll have to convince me that the polar ice caps are indeed melting, more than on a localized level, first. While in some areas, they may be shrinking, in other areas, they're growing, at just as fast of rate.

For fast corals, I'd go with Montipora digitata and moderate to high lighting. You'll need to have the same corals in each tank, so find a M. digitata colony and make 3 similar sized frags.

In order for this to be an experiment just about lower salinity, all over aspects of each tank will need to be identical. Other water parameters, temperature, lighting, distance of coral from lighting, flow...etc, will all have to be identical. In order to do that, you're going to probably need to have 3 different light fixtures, one above each tank. Otherwise, if you have 1 light fixture, lighting all 3 tanks, each tank will probably get more or less light than another. Although, you could accomplish this with a 36" 4 bulb T5HO fixture, probably.

 

[trido]

for a)

would xenia require the lighting that a lot of sps and lps require?

I grew xenia under a 4 foot 2x32W shop light in my sump. It doesnt require much light at all. Also xenia is known as a PO4 absorber, A few reefers use it instead of macroalgeas.

 

[mcdonaldjosh7]

yes, i planned on using the 36" fixture. and also, i know about all the controls...haha.

what would you say i should make the salinity levels? my idea was 1.021, 1.019, and 1.015

 

[mcdonaldjosh7]

Also, I was thinking about using a couple different types of corals in each tank (i.e. xeniz in each one, sps in each one [same type] and so on

does that sound like a bad idea?

 

[trido]

what would you say i should make the salinity levels? my idea was 1.021, 1.019, and 1.015

If your going to use SPS I'd suggest 1.026 as the highest reading. Its what most reefers keep their tanks at for a reason.

Take a look at this map. Most of the worlds reefs are in areas where the water is 35PPT,or 1.026

 

[akunochi]

linky no worky

 

[trido]

linky no worky

Worky for me after logging off line and then back in.

 

[Chichas01]

Yeah, ditto what Sid said regarding melting ice caps. Also, you have to work evaporation into that equation which would raise salinity levels. Why not simplify your project so it's not based on an unproven theory that most likely is false, i.e. global warming? The most complex computer models don't even accurately measure this.

You could do a project that measures growth of one type of coral under different types of lighting. Use the same coral under different lights in a system where water parameters are all the same maybe? Do 10K's work best? 12K's, 14 K's? This would be a lot easier to control.

 

[returnofsid]

Also, I was thinking about using a couple different types of corals in each tank (i.e. xeniz in each one, sps in each one [same type] and so on

does that sound like a bad idea?

Not a bad idea, if you can meet the lighting needs of both. To do this, you'll most likely need to go with T5HO, or even 150MH pendants over each tank.

You'll also need to make sure that each coral frag comes from the same colony. Otherwise, it won't be an accurate representation, as some colonies, even of the same species of coral, may grow faster than others.

 

[trido]

All very good points Sid.

unproven theory that most likely is false, i.e. global warming?

Really? you mean that the last ice age alone hasnt proven that global warming and cooling actually happens.
You do realize this is for a science fair? Most likely for school. Are you trying to start a global warming debate with a school kid? FWIW evaporation is a good point, we all take care of that though, by daily top offs whether manual or auto.

 

[returnofsid]

All very good points Sid.

FWIW evaporation is a good point, we all take care of that though, by daily top offs whether manual or auto.

I think the point was to attempt to determine how much the salinity in the ocean changes, due to evaporation, and to add that equation into this experiment. IMO, evaporation has no effect on our oceans salinity levels, since evaporation leads to rain, which makes it's way back to the oceans.

Another thing that may be considered, is the "advertised" changes in temperatures. If in fact, ice caps are melting, lowering the salinity of the ocean...one would have to assume that the temperatures of the oceans are also rising.

My concern, with this Science Fair experiment, is that it's only going to be approximately 4 months long. If the salinity level in our oceans is actually dropping, and if temperatures are actually rising, and if corals are actually being effected by this, it's an effect that's going to take hundreds or thousands of years. I don't know that a 4 month experiment is going to be able to duplicate this. For instance, lowering salinity, over a 4 month period will have a negative effect on corals, most likely. However, in nature, those same corals may acclimate themselves to these "glacially" slow changes that might take place. So, in nature, the same salinity drops, over a much longer period of time, might have no negative effect on the same corals.

 

[trido]

I think the point was to attempt to determine how much the salinity in the ocean changes, due to evaporation, and to add that equation into this experiment. IMO, evaporation has no effect on our oceans salinity levels, since evaporation leads to rain, which makes it's way back to the oceans.

Oh, OK, I misunderstood.
I agree completely.

IF, the reports of global warming are true. The polar caps likely won't be what kills off the reefs. It will be surface temperature and acidification due to elevated atmospheric levels of CO2.

This will be an interesting experiment nevertheless.

 

[returnofsid]

Oh, OK, I misunderstood.
I agree completely.

IF, the reports of global warming are true. The polar caps likely won't be what kills off the reefs. It will be surface temperature and acidification due to elevated atmospheric levels of CO2.

This will be an interesting experiment nevertheless.

That brings up another great point. In the experiment, should pH of the water be slowly dropped, as would happen in nature? If so, how much should the drop be and at what rate?

 

[trido]

That brings up another great point. In the experiment, should pH of the water be slowly dropped, as would happen in nature? If so, how much should the drop be and at what rate?

Sooooo many variables. I'd bet a few of us on this forum know quite a bit more about the oceans reefs (and the ocean in general) than most school science teachers.

Id bet if the test is kept simple and as scientific as possible it will make for a nice A+.

 

[sgwill122]

I would agree that a short term experiment will obviously be detrimental and really not prove a lot, but any experiment is worthwhile if you learn something, in this case it maybe coral husbandry. But if the pretext of the experiment is global warming is happening which will melt icecaps thereby decreasing ocean salinity harming our reefs, then I think you need to do a little more research on the subject, which should not take long. I would not want to debate global warming since it seems to be almost more of a political issue than scientific. But the assumption that if all the icecaps melted it would meaningfully impact ocean salinity is probably a bit off. The ocean has 1.3billion cubic meters of water, the icecaps have around 30million cubic meters or about 2% of the ocean volume. Assuming 100% of icecaps melts and the existing ocean average salinity is 35ppt, the resulting salinity would be 34.3. If you wanted your experiment to yield useful information about the impacts of melting icecaps on salinity and coral health, you would want to use a salinity delta's of less than 1 ppt between the control and experiment.

Heres a couple quick links I used for my info.
http://en.wikipedia.org/wiki/Ocean
http://www.johnstonsarchive.net/environment/waterworld.html
http://www.saltyzoo.com/SaltyCalcs/MakeupSalinity.php