acclimation of corals from vho to metal halide

[macronut]

This weekend I will finally get my 250 watt 10000k bulbs mounted in my new canopy. These will replace my very old vho bulbs that should have been replaced 4 months ago
(4@110watts 46.5"). I was thinking of running two 110watt super actinic for 10hrs per day all day (supplemental lighting). Then run the halides for 4-5 hours per day for the first week and increasing 1 hour every 4 days until I get to 10 or 12 hr photoperiod. Current corals are blue ridge, cup, zoo's, palythoa, ricordia and gorgonians (photosynthetic). I know it's going to be a shock so I want to acclimate the tank appropriately with the more intense lighting. The tank is a AGA 90gal. most corals can be moved to lower levels in the tank for help with acclimation. Sound ok?

 

[chris&barb]

sounds good but i would also add 5 or 6 layers of window screening across the top of the tank and after a week or two remove one layer every few days untill there gone then start to lengthen the photoperiod

 

[macronut]

Thanks. Nice clams on your site. How is the d. urchin doing? thinking about adding one.

 

[chris&barb]

thanks, the urchin is doing fine. the only problem is it will graze over corals from time to time. i have 3 kinds of urchins and he's the only one that ive ever seen eat coral. i have a bunch of Lytechinus variegatus. they are cheep and better then any snails or crabs for a clean up crew.

 

[Jobiwan]

If you can easily raise your hood that is another good way to acclimate to MH, raise it 8 -10 inches and lower it a couple of inches a week....

 

[fly guy]

Personally I think raising and lowering the lights and adding layers is kind of a unecessary PITA.

I think keeping your actinics on for the 10 or 12 hours you mention is fine but instantly starting at 4-5 hours for the halides is too much. Set the halides where youw ant them to stay and then start out at 2 hours or so.....add a 1/2 hr every 4 or 5 days until your system tells you its enough then back it off to where it was before you added that last half hour. I wouldnt be set on the end poiint being 10 hrs for the halides. Everyones tank is different and you need to find the sweet spot for you


Just my opinion and how i would do it

 

[macronut]

Thanks. I'll consider this. I plan on having the lights on just in the early evening when I'm home so I can keep an eye on the tank. The supplemental lighting will stay on regular schedule. I may only run halides for 8-10 hours once everything is acclimated.

I completed the canopy today by attaching the doors on front and a lid on top, plus mounting the fans. The lights will be mounted on Sunday. The halides have reflectors and I'm debating on mounting them 3/4" from the lid or just screwing the reflector onto the lid itself. If I drop the lights 3/4" this will allow more circulation of air around the entire halide unit. Not sure what I am going to do? I need to make up my mind.