Question About LED Coverage

**SubRosa** · 07-31-2012, 6:05 AM

I have a customer tank whose owner wants to make the jump to LEDs. Bulb replacement time coincided with the chiller crapping out, so it's probably the smartest time to do it. I've done a few retrofits of the Blueline VHO strips (most of my customers have decorative canopies that the lights have to fit in), but have absolutely no experience with the pendant style fixtures. The tank is 60"L x 24"W x 25"H and is lit by 8 x 54W T5 HOs. Corals are a mix of SPS (Caps, a couple of easier Acros) and LPS (Euphyllia, Favia, Plerogyra) which all show good color and grow nicely. The customer is interested in both the Kessil A350 and the Radion XR 30 units. I'm going to remove the top panel of the canopy to allow the lights to be suspended at whatever height I need. My question is whether or not I can get by with just 2 of either unit and still maintain even coverage, or whether 3 will be required. TIA!

**Narwhal72** · 07-31-2012, 8:10 AM

Depending on how the tank is braced and the way the rock is stacked you may be able to get away with two but I think 3 would be better. If the tank has a single center brace then putting a pendant on either side of the brace should work. You may have some shadowing in the center and the sides. If you put 3 in the center brace will block a lot of light. It may be better to put in 4 of the smaller Kessil's.

If the tank has two braces then I would go with three pendants.

Andy

**SubRosa** · 07-31-2012, 8:14 AM

It's an Oceanic, so it has a wide glass brace in the center.

**Narwhal72** · 07-31-2012, 11:14 AM

It still has that plastic little strip that separates the glass canopies but it's not as thick as an injection molded framed tank which is good. Assuming that you keep the algae off the underside of the center brace that is.

I would probably start with two Radions then. If the shadowing in the middle between the two is too much then you could always add a third in the center.

One of the disadvantages to LED's is that the light is very directional and narrowly focused which reduces coverage area. But it does increase efficiency in the areas that it does cover.

Andy

**greech** · 07-31-2012, 8:41 PM

The problem you will have with the Kessils (and I do love these lights) is that you need to accomplish 2 things in this case (spread 60x24" and a decent depth at 25"). The A350 only has a 30 degree beam angle while the A350W has a 70 degree angle. You'll need to mount either fairly high up to get the coverage and then your issue will be getting enough light in the lower areas of the tank. This points to the A350 but you will need 3 at a minimum and most likely 4 to get the coverage you customer is currently getting with T5s. Honestly, from what I have seen, you'll need 3 x A350W to get what you want. There is a 90G (mainly LPS) in town with 2 on it and that is just a little short of being perfect at about 16" above the water. The other issue with these is that they are either on or off and you'll need to rig up some kind of structure should you decide to add any supplemental lighting (nothing to mount to).

I have no doubt you will need 3 radions to cover a 5'x2' tank. No problems getting to the bottom though. The added benefit his is the ability to program then to ramp up and down on their own reducing the need for supplemental lighting. This pretty much makes the 2 options a wash in terms of cost.

Of course, aquascape and coral placement has a lot to do with it so if lower light LPS can be placed on the edges you might be ok with 2 but you need to tell you customer that they shouldn't expect their tank to look nearly as bright as it is currently under a 8 bulb T5 fixture. Not saying the lights won't grow coral, they certainly will but the appearance will be dimmer. I'm sure you know this but be very careful about acclimation. It is so easy to bleach corals when you move into the higher end LED fixtures.

If your customer is willing to drop $2400 on 3 radions then just do this and call it a day...

http://premiumaquatics.com/aquatic-s...LF-S26012.html

**SubRosa** · 08-01-2012, 8:01 AM

Thanks for all of the replies! Given that the money is pretty much a wash, and since the customer already has the wireless Vortechs for water movement, the fact that the Radions can interact with the same controller will probably seal the deal.