digital_gods

Now that we have all the par data of all the club members tanks, we can get a better idea of what light requirements are needed for each tank and a idea of par requirements for different plants. I got some clippings that are from Coral & Reef USA - 2012 Annual to help us Brain Storm a better guide for aquatic plants. I got an ad from AquaticLife that actually give a lot of information in a info graphic format. They give us the tank footprint, corresponding lights they have available and what can be housed in the tank based off tank height. Next clipping is a chart of corals par requirements in a grouped form. I think this is be a great idea to come up with something similar for plants. The last clipping is just to show par at different level in the tank and the placement of different corals groups in a tank based on par and tank depth. I think is would be great to come up with something similar that is applied to aquatic plants that would give visual explanation of how much light is loss in aquarium.

--Robert

Michael

These kinds of charts and recommendations for PAR levels in the species accounts in the Plant Finder are what I hope will come out of this. But at this stage we need a lot more data.

So, members, borrow the PAR meter and post your results! Right now the meter is available.

Newt

This is a nice project you guys and gals are working on. PAR is more useful info but still has draw backs. PAR does not differentiate the wavelenth (color)of light as does PUR (this also has draw backs)

A few facts to keep in mind while evaluating your data:

As light passes through water the intensity decreases. The shorter wavelength blue light penetrates water better and more quickly than red, which is slower and absorbed more quickly. Chlorophyll, the photosynthetic pigment used by plants traps blue and red light but is more efficient with red light. Blue is used at the same rate as red - one photon of either red or blue produces the same amount of photosynthetic action.

digital_gods

The most accurate way of determining the necessary par per plant would to use a Junior PAM http://Walz.com/products/chl_p700/ju...roduction.html. This little device does it all except french fries for low low price of $3300.

fishyjoe24

isn't foreverknight jason building something like that but for much cheaper?

foreverknight

nope joey i'm building a spectrometer that allows you to get a general measurement of the intensity of the different colors of light being produced by any one source

Newt

Thats the way to go. You going to make normalized spectral output graphs?

foreverknight

that is the plan to an extent newt I found this article on the internet and a project group that has made them and a program to interpret the data. here is the link just for you and anyone else interested. If anyone would like to build one themselves i can help with the build. after I get the build done i will work on seeing if the program works on windows computers it says it should but those of you with mac and linux experience will be ready to go. I'm personally a little behind on my mac and linux work lol.

here is the link
http://publiclaboratory.org/wiki/vid...r-construction

p.s. after i get done with this out of water version i will be trying to adapt the design for aquatic use.

Michael

I understand the differential absorbtion of the red and blue wavelenghts as depth increases. But since a PAR meter measures total photosynthetically active radiation, how does this make it less accurate than a spectrometer for our purposes?

foreverknight

the led issue is one of them but hope to have that solved really soon....