Par

[charlie]

If you have an interest in what some lights do par wise, this guy did some testing of some lights including the ADA Aquasky, have fun  - need Google translator.
http://prirodni-akvarium.cz/index.php?id=mereni

[wolfiewill]

Google Chrome will do it automatically after getting your approval.

[exv152]

To think I'm getting 125-145 µmol PAR at the substrate with my aquasky 601 is really surprising. I read another guy who did PAR readings on his 601 on TPT forum and he got 70 µmol PAR at the substrate (with the same tank). So I find it hard to believe who's providing accurate stats, in either case both are good results and I'm very happy with mine.

[exv152]

I found the following excerpt fascinating, it does follow some of hoppy's theories with PAR measurements from TPT...

I will investigate the exact impact of these variables on the final results later. [For now I can only say that when the light goes through the water surface, it drops in intensity by 10-20 μmol PAR]. On the other hand, the existing measurement suggests that the values under water (i.e. in the tank full of water) will be probably 2- to 3-times higher than the values measured "outside the tank". This means that if we get 50 μmol PAR outside the tank, then in the tank (underwater) we can have up to 100-150 μmol PAR. In other words, if you want to find out how much light (μmol PAR) your lighting produces underwater, multiply the values shown here by the coeficient of 2 to 3.