View Full Version : Do I have my Photon V2 set to bright?

12/05/2016, 12:19 PM

I have a 48" Photon V2 over a 55-gallon reef tank (48" x 12" x 21"). The tank was started about 3 months ago, and the light is mounted about 8" above the water. I began stocking it a month ago with a cleanup crew, and about 3 weeks ago I added a pair of ocellaris clowns. Two weeks ago I added some green star polyps. All residents seem to be healthy.

A few days ago coralline algae started to take off - but it is growing mostly on the shady parts of the rock. I had assumed that it would grow most quickly in the brightest areas when it started. Also, the two clowns spend most of their time swimming in shaded areas during the afternoon, when the lights are brightest. The green star polyps are doing well about 7" below the top of the aquarium.

The lights start low and ramp up for six hours, then back down for six hours. Maximum intensity is at 2:00 PM:

Red: 18
Green: 15
Royal Blue: 60
White: 36
Cool Blue: 30
Violet: 30

Does the growth of coralline in shaded areas and the shade-seeking of the ocellaris clowns indicate that the light is too bright? Or are these observations normal? This is my first reef tank. I started the lights about 2 months ago with the same ratio as above, but Royal Blue maxed at 30. The current intensities have been set for about two weeks.



Ron Reefman
12/06/2016, 06:04 AM
Hi Don. This is all just my opinion and experience, so don't take it as proven fact. Hopefully others will follow with their thoughts. And the short version of my answer is no and here is why:

I have a V2 50" over a 60"x24"x20" (125g) tank and mostly acclimated sps and lps corals. My fixture is 13" off the water (on the longer side of the legs). I do a 5 hour sunrise ramp up, a 5 hour midday and a 6 hour sunset ramp down. My midday is red 0, green 0, royal blue 80, white 40, blue 90, violet 40. I figure the last hour of my sunrise and the first hour of my sunset are close enough to the midday number that I get 7 hours of good intense light for photosynthesis. The zooxanthellae (algae) that is inside your coral and does the photosynthesis to feed it needs and hour to get started and then after 4 to 6 hours of photosynthesis it will shut down even if you continue to provide bright light. BTW, I have a PAR meter so I have a fairly good idea of just how strong my light is. And I have a big colony of War Coral that is only 4" under the water surface. So you have probably started low enough, although not as low as many. After 3 months I'm sure your current livestock is acclimated to your levels. If you decide to go any higher, do it very slowly, like 5% up on blue or white only every 2 weeks. But no, in my opinion your levels are not too high and the peak may not last quite long enough.

I'm unsure about the coraline growing in the shady areas. It could be that diatom algae on the bright side is temporarily blocking the coraline? That's just a WAG (wild a** guess). But at 3 months your tank and mine are the same age and I don't think I have any coraline algae growth yet. At 3 months you are 3 to 9 months away from becoming a 'mature' tank which is when things get much more stable.

My tank is a rebuild from a 180g that broke. The sand is washed and about 40% of the rock was dry and the rest was very alive in the old tank. But my corals, mostly sps and lps went in under fairly high led setting because they had been under similar levels in the old tank with old Photon leds. I had zero cycle with ammonia, nitrite and nitrate, probably due to the amount of live rock. However, I did have some serious issues with diatom algae because it was on everything. I would blow it off the corals every day or two with a turkey baster. I did a couple of blue leds only for 3 or 4 days and the diatoms would be greatly reduced. I did some some water changes after 6 and 8 weeks. Now the tank is looking pretty good, but no new coraline that I can see. It may be growing on the old rocks, but I'd be hard pressed to say with all the coral on the rocks.

As for the clowns, they have a mind of their own. More often than not they tend to find a small area in the tank to claim as their own and they tend to stay there most of the time. IMHO, I seriously doubt that the lights are the driving issue with the clowns.

The display refugium that looks much warmer color was added after the main tank had been running for 2 months. I think it has helped cut down the nitrates and phosphates some and nuisance algae in the main tank has been reduced.

http://i395.photobucket.com/albums/pp37/RonReefman/20161018_170631_zpsfaas63gv.jpg (http://s395.photobucket.com/user/RonReefman/media/20161018_170631_zpsfaas63gv.jpg.html)

12/07/2016, 04:01 AM
Thanks for the insight Ron. I think you may be right about the diatoms suppressing the growth of coralline on the tops of the rocks. I had a substantial diatom bloom that is just about past now.

Since all the inhabitants seem healthy, I will leave the lighting as it is now.