halide upgrade-need help!

[bv_reefer]

well i currently have a great oppurtunity to upgrade my lighting from 2x70-watt hqi's, to a 1x400-watt. Again this is for my 33-gallon. I'm really nervous about it because it's a jump from 4.2watts/g to 12.12watts/g. But the absolute last thing i need is all my soft corals and lps bleaching from it, what can i do to avoid bleaching or shock. where and how high should the bulb be from the surface of my water, my current bulbs are about 5'' from the water surface. any suggestions greatly appreciated-

[michika]

For starters hang your new 400w bulb higher, say 10". You can slowly over time adjust it lower. You can also try multiple layers of mesh and remove one layer at a time over the course of a few weeks.

[bv_reefer]

so you think that by hanging it about 10''-12'' from the surface, my corals won't bleach? is hanging it high enough or will i have to put layers of eggcrate or mesh too?

[michika]

You may want to do both, and you can also consider reducing your photoperiod.

[bv_reefer]

my photoperiod is currently 12 hours, from noon to mid-night, so i think i'll start by hanging it 12'' abover water surface, couple layers of eggcrate, and reducing photoperiod to 8 hours to start, thanks again

[Reefer Rob]

8 hours of 400W is a lot of light (especially for a 33 gal). I think that should be your max! You might get away with more with a 14K or 20K bulb. I would start with 4 hours or less and work up slowly. Keep a close eye on your corals, and be ready to dial it back if you see any distress. Do you have a chiller?

[bv_reefer]

no i don't have a chiller but i'll keep the bulb at 12'' above the surface to reduce the heat, and i guess turn the heater down a bit if that helps

[Drock169]

400 seems overkill to me, I wouldnt have gone with more than a 250. But I agree with everyone else, increase height from surface, reduce photoperiod, and use a higher K bulb.

[bv_reefer]

i'm getting an XM-400 watt 14k bulb, 12'' off the surface minimum, start a photoperiod of 3-4 hours, gradually work it up to 6-8 hours-

heres all my corals and inverts, think any of them will take the lighting change really negatively?

-xenia colony, ricordea, 2xfinger leather colonys, monti cap,cup coral(lps one), kenya tree, long tentacle plate coral, condy anemone, green star polyps-

[michika]

400w is okay, I did it on a 46g and got great results. Just remember to watch your temperature and be ready to acclimate all your new purchases in the future.

[Reefer Rob]

Looks like you have under control. Just make sure you keep a close eye on your corals for signs of stress. You'll be riding the ragged edge with that setup; the outcome will either be glorious or disastrous :wink:

Oh, I see you're getting the XM 14K bulb (isn't that 15K?), a notoriously low par bulb. Should be your safest choice for that setup.

[Jason McK]

Oh, I see you're getting the XM 14K bulb (isn't that 15K?), a notoriously low par bulb. Should be your safest choice for that setup.


Agree it will be great for acclimation but you might want to switch them with a higher par bulb later. What Ballast are you going to use?

J

[bv_reefer]

the type of the ballast i will find out today, but what do you meen higher par?
does that meen higher kelvin, or better quality bulb?

[Reefer Rob]

"Photosynthetic Available Radiation" or something like that.

Here's the best halide info on the web:
Sanjay's Website (http://www.reeflightinginfo.arvixe.com/)

[bv_reefer]

ok i'll ask for that when i go buy a new bulb. i think the XM-15k should be fine

[bv_reefer]

so with a 400-watt over my 33-gallon, can i pretty much keep all the acros, milliporas, and clams, that need high light?

[michika]

so with a 400-watt over my 33-gallon, can i pretty much keep all the acros, milliporas, and clams, that need high light?

Yup you should be able to. You may need to put LPS into shadier areas though.

[NateL]

You will probibly have some darker areas on either end of your tank with it being 3ft wide and using only 1 central light. Probibly not much, but it might be better areas for your LPS and softies.

Nate

[bv_reefer]

all my softies are on the sides other than my xenia who is right in the middle, so i fear the worst for him, but i think he shud be ok, my cup coral loves light so he'll be ok and colt also worrys me even though he's on the bottom of the tank, all the way to the left