Switched To Finnex Ray 2

[Trickerie]

Hey all,

My original setup was 2 T5NO fixtures (4 bulbs total), one on the back, and one on the front of my 25g. I recently received the 24" DD Ray 2 as a birthday gift, and was thrilled to have it. But, I've been noticing a few things.

First, I highly doubt this, but is it possible I'm actually receiving less PAR than I was with the dual NO's?

Second, it seems the coverage of my light is less. My creeping jenny has lots of "dark" areas. The leaves on the top are growing awesome, yet the ones on the bottom are rotting. What can I do to increase coverage? Is there a "sweet spot" to place the fixture? I have it close to the middle of the tank currently and it seems to give the best light that way.

My had two qualms about this fixture. First, since my tank is 20" high, I'm hoping the light penetration is sufficient at all depths. Finally, the LED's are 10000k/7000k. I know this fixture was made specifically for plants, but the temperature just seems odd to me. Hopefully I'm wrong.

[Hoppy]

If you needed two 2 bulb T5NO lights on that tank, a single LED light isn't going to give you enough coverage of the whole tank. What are the tank dimensions?

[Trickerie]

The tank is:

24"L x 13"W x 19"H

Heres a picture, if it helps:



You can see my micro swords are browning, and the bottom right corner of the creeping jenny, where its darker, is as well.

[Trickerie]

I was curious so I put one of my Coralife T5NO fixtures back on with the Finnex. After about 5 minutes two of my swords began to pearl. Maybe the Finnex light just isn't a good fit? I sort of wish I would have gotten the catalina dual switch t5HO instead :|

[Hoppy]

Based on the data from the manufacturer the Finnex light should be giving you 35-40 micromols of PAR, and the T5NO should be giving you about 20 micromols or less, based on the data I have. Either the T5NO light is better than the Coralife light I have data on, or the Finnex data is overly optimistic.

[Trickerie]

So, using the low end of these numbers, using 1 CoraLife fixture, and the Finnex fixture should be me at about 55 PAR, which is good medium light, yes? Does PAR work like that? Even though its not coming from 1 fixture. I'd assume that some spots may have drastically less, due to the coverage each fixture offers. Meh.

My CoraLife fixtures have the "fair" reflectors depicted in the par vs distance thread.

I'm really trying to find a balance here. Ive got good co2 levels with my diy co2 (constant light green/yellow), and I dose ferts using PPS Pro. However, my microswords tips are browning/curling and my creeping jennys leaves are getting transparent spots

[Hoppy]

If the light from two bulbs or fixtures overlaps, the PARs add up. Most bulb/reflector combinations give the highest PAR right under them, which drops as you move farther away from them. How fast the PAR drops depends on the reflector, or, for LED lights it depends on the optics used and how close together the rows of lights are. It should be possible to put two bulbs/lights side by side at a distance so the PAR remains reasonably constant from a little distance on the side of one bulb all the way to a little distance from the other side of the other bulb. With little data it looks like that distance, for T5HO lights with good reflectors, is around 6" more or less. So, with a 12 inch front to back depth tank, two bulbs 6 inches or so apart can give you nearly uniform PAR all the way from the front glass to the back glass. I don't see any benefit to combining a Finnex LED light with a T5HO light.

[odie]

An issue I have seen with heavy filled coral tanks is that the corals create shadowing much easier with leds than with T-5. I often times wonder if this will be a problem in larger planted aquariums.

[Trickerie]

Originally Posted by odie

An issue I have seen with heavy filled coral tanks is that the corals create shadowing much easier with leds than with T-5. I often times wonder if this will be a problem in larger planted aquariums.

For sure. I had to hack away so many sword leaves yesterday, they were just out of control and obstructing so much light.

I guess the problem is that t5's can have amazing reflectors, helping the spread of the light.