SENEYE and the importance of PUR

[Aqua-Digital]

One of the biggest reasons SENEYE has become very popular around the world with the Reef Keeper is its built in Light meter that reads PAR Kelvin LUX AND PUR.

PUR maybe not be that common a term with many but probably is one of the most imprtant readings for the average hobbyist especially who is not an aspiring physics teacher!

What is PUR?
PUR stands for Photo-synthetically Usable Radiation. It is not a scientific term, like PAR, but can be more useful regarding aquaria as different photosynthetic species (plants, anemones, corals) have different PUR levels, though they may all be within the same PAR. Essentially the PUR is a more focused term describing the specific PAR levels used by each species.

Still confused? Ok PUR is in raw form a reading of usable (growing) light, so the better the reading the better the growth at that reading point. This is a fantastic tool for the average hobbyist that wants to see if their lamp is set at a light level to create the best growing environment. And this is where SENEYE not only differ but provide a very affordable option for measuring your lighting output

How can I check? A useful device for reef tank keepers - Seneye Reef
PAR and PUR are things that reef tank keepers should be aware of. If not actively monitoring your lights, it would still behove you to know about how PAR affects coral, and which PUR levels your corals need, so informing your choice of lights at purchase.

You can use a visible light spectrometer to check the PAR levels of lights, though this would only allow you to make light readings from outside the tank. In order to ascertain the PAR levels within the tank, you will need a specific light monitoring system (such as the one incorporated in the Seneye Reef device) allowing you to take readings underwater and if necessary at different levels of the tank to establish which areas are most suited for corals.

Light degrades in intensity (measured in lux) and spectral quality as it passes through water due to interference (see Fig. 2). The PAR level drops because certain wavelengths of light (the blue end) find it easier to penetrate the water to depth whereas the other colours find it increasingly difficult and so are stopped at different levels.

Fig. 3 Approximate distribution of PAR (in nanometers) from 2x 250W halide bulbs (B) positioned centrally above an aquarium



A lux reading shows the level of occurrence of perceived luminous flux (the amount of light) in a particular area. If the light is too intense or too weak, photosynthesis will not be able to occur regardless of whether the spectral elements of the light are adjusted to support plant life. Again, the drop in lux is due to the interference of the water. Fig 4. Shows the correlation and though there are no specific units shown (for each type of zooxanthellae the values will vary), the gist of the matter is clear.

Fig. 4 Suitable light levels for corals



Unlike stand-alone PAR meters, the light meter on the Seneye Reef device will also measure lux and Kelvin, allowing you to check that the light intensity at different levels within the tank is suitable for your corals. PAR and lux measure the light in terms of the amount of photons available. Kelvin and PUR (there is an icon to click on the Seneye download which shows the PUR) measure the quality, and this is worth knowing with regard to your particular corals.

Here is a screen shot of what you can expect to see



The PUR aspect is only available when the Seneye Reef is run through the SWS (SENEYE Web Server), the rest are available through the downloaded software for PCs



Of course SENEYE is far more than just a highly functional light meter so for the base price of $159.00CAD there is a lot of value in one box!
SENEYE WEB SERVER Sold Separate

To order please contact your LFS or email us where to buy sales@aqua-digital.com

Come join us also on Facebook
https://www.facebook.com/groups/aquariumgroups/
https://www.facebook.com/seneye