finnex ray 2 on 75 gallon

[jester56]

Originally Posted by Oxl

I've been eyeing that light fixture, nice thing about it is that it is so narrow that it would be simple to add more units if one proves to be insufficient.

I have 2 36" Ray II fixtures on a 50 gal. Only drawing 29 watts for the daylight 290 LED model, these things throw an awesome amount of light. After what Hoppy said, I'm considering hanging mine from the ceiling. Radiant heat is almost non existent. I can pick one up in the center and it is barely warm. I'm a fan!

[houseofcards]

Originally Posted by Hoppy

...I found that the intensity with water is a bit higher than without water. Eventually I figured out that the air to water interface acts to slightly focus the light, increasing the intensity, plus, for most tanks, you get some light reflected off the front and back glass, which also increases the intensity. After that I started just measuring PAR out in the air.

All we are doing is stating that a light which produces XX PAR at YY distance, in air, will give you low or medium or high, etc. light in a tank that has the light YY distance from the substrate. Of course in a tank of water, even with no plants, the PAR varies a lot from one location to another in the tank.

So why do those fishes under the water develop their own light systems. What the sun doesn't have enough PAR, LOL. So at what point does water hinder light intensity rather than enhance it?

[houseofcards]

Originally Posted by jgc

In addition to the refraction of the light as it enters the water (essentially creating a lens), there is now a water/glass rather than an air/glass interface which I suspect reflects more light (plus that light is at a different angle when it hits the glass causing greater reflection).

meh.. you can throw a lot of science on this, but home aquariums are not controlled science experiments. Any manufacturer will state their highest, most desirable numbers in a controlled setting, but it's really not 'real life' In the same way my car is suppose to get 40 mpg, but only get's 30. I guess the auto manufacturer forget that in real life people don't drive in wind tunnels, and they don't keep a constant speed of 50. And the biggest surprise is they actually have other people in the car too. On thing your forgetting is the tank the light goes on is not empty there will be hardscape and other plants in the way, there will be surface movement and water that isn't crystal clear like the air. Some light can also be reflected up and out or away from the plants. So give me PAR through air and an empty tank and I'll give you a Jeep that think's it's a Prius.

[jgc]

agreed - everything we do is an estimation. More of an art than a science. PAR in Air gives us a good comparable baseline.

That said, I now have I week with the Ray II on my tank. While much less light than my HQI Metal Halide - I am getting much better growth with the Ray II than I expected (abet I expected to see plants gradually melting away - so any growth is much better than I expected). Lots of new shoots and leaves. Makes me more optimistic.

[houseofcards]

Originally Posted by jgc

agreed - everything we do is an estimation. More of an art than a science. PAR in Air gives us a good comparable baseline.

That said, I now have I week with the Ray II on my tank. While much less light than my HQI Metal Halide - I am getting much better growth with the Ray II than I expected (abet I expected to see plants gradually melting away - so any growth is much better than I expected). Lots of new shoots and leaves. Makes me more optimistic.

Just keeping it real, but yes I agree. That's good to hear that your getting growth after the switch. What kind of plants are you growing?