|Topic Review (Newest First)|
|02-08-2013 09:27 AM|
I imagine a lot depends on what your prof wants you to get out of this...
Anyways, I like bikinibottom's suggestion, the whole siesta-period bit tends to stir up controversy, so if you could set up a couple of small tanks (again, depending on how rigorous your prof wants it...) with floating plants (measure weight before putting in, try to approximately equal amounts to all tanks, and measure again weight again at the end of the experimental period). Although it would be pretty hard to quantify, it would be pretty low effort to also take pics of the tanks at regular intervals. especially if you end up doing some sort of poster or something, a beginning, middle, and end pic of siesta versus continuous photoperiod (if there is a difference) can add a lot of interest to the write-up, even if you all you have is 'this looks like it grew more'
btw, do you have access to any sort of equipment for measuring/testing, or is your class focusing on lowtech/lowbudget types of projects?
|02-08-2013 05:15 AM|
Originally Posted by manzpants92 View Post
This will have a very high growth rate/response.
You might do a CO2 enrichment vs non CO2 enrichment growth comparison.
You can still use the SAME tank, but you do each test as a block.
So weeks 0-2: 1 Block, say non CO2.
Week's 2-4 Block 2 , say CO2. I'd do at least 2 replications.
Add a student's t test and Y error bars.
Then make an argument about how weeds will grow faster with increasing man made CO2 enrichment into the air etc. Should get a decent grade.
If you can vary the light intensity, you can also do an experiment on cytoplasmic streaming inside live Egeria densa plant cells. You will need a microscope with a scale on it. Then state why the chloroplast are increasing or decreasing their speed.
You can also use DIY years for CO2 source, cost: free pretty much.
Duckweed or Azolla are always favorites.
You could measure copper or any heavy metal toxicity in small test wells.
|02-07-2013 11:45 PM|
I've been planning an experiment that maybe you might want to try. In Diana Walstad's book she talks about a "siesta" lighting regimen on low-tech tanks. Basically she turns the light on for 4 hours, off for 4 (during which the tank gets a lot of natural light), and back on for 4. She has a graph in her book that shows that CO2 gets depleted almost to zero in the first 4 hours, but rebounds while the lights are off. So the theory is that low-tech tanks on a siesta regimen will get more CO2 and thus grow better. I think the big question mark is in the latter part of that statement -- do they actually grow better?
An experiment you could try is setting up two identical tanks -- same everything including the size/shape, substrate, water source, dosing, type and number of plants, temperature, water flow/filter, etc. (and I would keep it to one type of plant so that plant interactions don't impact your results) -- except one tank is on a 12-hour constant-on lighting regimen, the other on a siesta regimen. You can measure the height of the plants and number of leaves (assuming you don't use something really tedious to count like myrio), and then re-measure after a 2 or 3 month period.
Practical real-world application? None really, but you could argue that if the method is "better" for plants, and every planted tank enthusiast then switched to using a siesta regimen, then it would reduce electricity usage by a third, making the hobby more eco-friendly.
|02-07-2013 09:49 PM|
A classic type of experiment with 2 identical tanks, and just change one variable between them and compare results at different time intervuls. (makes a nice line graph!)
One applicable to a real world situation would be more meaningfull. such as add simulated farm runoff to one and pure water in the other. I would hypothesize that the one with "farm runoff" ie. nutrients. will grow faster.
Ooh, or a fun one with one tank would be put all native plants to your state (wild collected) and one on your states invasive sp. list (SnS!) all in one tank. Interspecific compitition between natives and non-natives would be fun!
I could go on for days, this is kind of what im doing at work and in my free time, But for fish populations.
|02-07-2013 08:47 PM|
As of now i don't have a "set experiment" that i wanna carry out. Any suggestions would be good!
I was thinking either something that involves growth of plants under certain conditions or possibly if plants would take up enough nutrients to avoid filtration. As of now I'm just trying to gather idea's
My bulb that im using is just a spiral CFL 27W. I have a window in my room so I have the option of avoiding sunlight or making it available
|02-07-2013 06:17 PM|
|Hawkian||I've had termendous success keeping hygrophila polysperma in a low-light setup... and it will grow like a weed (oh wait... it is a weed...huh!)|
|02-07-2013 05:00 PM|
It'd be easier to recommend plants if we had some idea of what your experiment was going to test. Also, what lighting will you be using? Yes, a desk lamp-but what type of bulb and will the tank recieve supplemental sunlight?
If you're using a high lumen bulb in the lamp and/or the tank is exposed to indirect sunlight during the day--you may be much better off with faster growing stems so you get enough growth (even if less than optimal growth patterns under the lower light conditions) to obtain measurable changes in the plants.
|02-07-2013 04:48 PM|
|DogFish||Actually an experiment that utilizes DuckWeed as a renewable bio filter might have some merit. Just not sure how that can be pulled off in now 2.5gl tank???|
|02-07-2013 04:17 PM|
Originally Posted by DogFish View Post
|02-07-2013 12:03 PM|
Originally Posted by Darkblade48 View Post
Hornwort likes cooler water temps, Water lettuce, will stay small but still grow rather rapidly with low light, and the nearly impossible to kill duckweed will work.
|02-07-2013 08:58 AM|
|Darkblade48||Mosses, Cryptocoryne species, Anubias species, and Java Fern are some of the names that come immediately to mind.|
|02-07-2013 07:18 AM|
designing an experiment
Hey all, this semester I'm taking a botany class and we have a big semester project and I decided to do something with a planted tank. I picked up a 2.5 last week and a nice desk light. What are some good low tech plants i won't need co2 for? And what substrate would be recommended? Any other help or advice would be great