Light acclimation.. One frag unhappy..

[One_Divided]

I just added a second 175 10k halide to my 33 to keep the sps happy till my 50 is set up and stable.

So the tank is now: 2 175w 10k halides and 2 2" actinic vhos.

How do you think I should acclimate to the new light? I was thinking of starting at four or five hours and adding maybe a half hour a day till I am at full photo.. What do you guys think?

[ 26 February 2002: Message edited by: One_Divided ]</p>

[George]

Gradually building up photoperiod is always a safer way.

Howerver, if it was my setup, I would just blast the coral with both MH at current photoperiod.

HTH
George

[ 25 February 2002: Message edited by: George ]</p>

[titus]

Hello,

You can raise the MH so it is higher from the tank.

[Delphinus]

Blasting the corals with twice the intensity you had before, at full photoperiod, is a sure way to fry your corals. I'm sorry George, but I have to disagree with you on that one...

Even just a reduced photoperiod at full intensity is asking for trouble IMO.

The best way, IMO, is to reduce the intensity, either by raising the lights, or, by some other means. And then gradually ramp up the intensity over time until at 100% (i.e., lower the lights every day or two, until at the desired height.)

What I've also seen done in canopies where raising the lights or canopy wasn't an option, was a few layers of eggcrate. Four of five layers, and the guy removed one layer every 2-3 days.

I once had a halide bulb crack its casing (completely in two pieces). The piece at the end slid off about 1". It took me about 2 hours to notice that something was amiss in the tank. But the reason I did notice something was amiss was one of my acroporas, the one closest to the light, had completely fried. White as snow -- it was gone. Two hours. This is a slight apples to oranges comparison, but it goes to show that a sudden enough increase in UV is enough to kill corals, even corals that are generally regarded as "high-intensity-lighting required" corals ... ALWAYS go slow when changing things around.

If I were in your situation ... and I couldn't raise my lights and slowly lower them over time (which would be my first preference), and I also couldn't possibly go with eggcrate .... then my initial photoperiod on the second bulb would be no more than one hour for starters. I may be overly paranoid but I'm sorry if there's one thing I have learned is that it is exceptionally easy to go too fast in this hobby.

Good luck!

[One_Divided]

thanks guys. I don't have the option to raise lights or do the eggcrate thing so I am just going to have to slowly acclimate.. I started at 4 hours today and 2 yesterday (wasn't done till late in the day). I guess I will add a half hour every second day?

Yes it is twice the light, but it is distributed differently.. on either side rather then right in the middle.. so coralstowards the middle are getting just about the same amount of light.

I have seen no negative reactions yet to the light.. some corals are expenading even more then ever today.. I'm keeping a close watch anyway.

[SuperFudge]

Im not sure it was the lights even,or that the frag is even bleaching to be honest.
Usually the tips(or side closest to the light) will show the first signs of light related bleaching(IMO).

Hard to tell forsure but it doesnt look as if there is any tissue in that area at all.

Bleaching from your lights would probably take about a week to really show itself,and all branches at the highest points would show signs of it.

Its been about a 6 weeks right?...it should have had good signs of encrusting by now...if not it may well just be dying from the base up or touched another frag or coral in that area.

If its needs are met,and it was bleached...it will slowly color back to its original color in that area,after light acclimation.If it were dying,the area will cover in green diatoms within days and will need to re-encrust back down the base.

Keep us updated,Marc.

[ 26 February 2002: Message edited by: Superfudge ]</p>

[One_Divided]

thanks marc.. I just noticed a strong possibility that it was a shroom next to it.. does acro usually take a fair bit of damage from shrooms? I poked it and it had receeded for now.. I'll scrape the shroom off later.

This frags has been healthy and growing up untill now, so that's why I suspected the lighting.. but it could be a lot of things I guess

[SuperFudge]

Shrooms are probably the worst niehbors [img]images/smiles/icon_wink.gif[/img] .

Good luck,
Marc.

[ 26 February 2002: Message edited by: Superfudge ]</p>

[Delphinus]

I concur with the mushroom damage theory (or some other kind of "territorial dispute"). No anemones near your SPS, right?

The few times I've seen bleaching caused by light shock, it was more of a systemic bleaching. It's kind of hard to describe, but basically each polyp would have a bit of bleaching and then each spot of bleaching would grow, until they all met, at which point there was nothing but skeleton. (In the time that I mentioned about where my halide bulb lost its casing, the burned acro was nothing but bare skeleton when I even noticed it. The lights hadn't been on for more than 2 hours. It was just dumb luck that I happened to be home for lunch that day. Otherwise it could have been another six hours before I got home and noticed something wrong. But ... that's another story!)

I think you're doing the right thing by observing closely. I would guess you're on the right track: if the polyps are extending just fine then presumably it must be OK with the new light. Good luck!

[One_Divided]

thanks guys.. all polyps on every coral are opened exactly as usual, if not more on some.

Man I don't ,know why I obsess over these little things so much heheh..