SPS, MH and bulb distance

reefknot · #1 02-09-2011, 02:33 PM

Yet another thread that has caught my attention, so much wealth of info on this great site, thankyou everyone.
I am fairly new at this hobby and have just started to collect some SPS. I have a 48" x 30 " tall x 18" tank and I have got 2 x 400W mogel base MH set at 17 " above water, ( that is the bulb ) it gives good coverage and appears to reach the depth okay, I guess time will tell, lol I also run two T5 454
any hints or suggestions always greatly appreciated.
Kevan

Aquattro · #2 02-09-2011, 02:55 PM

Quote:

Originally Posted by reefknot

I have got 2 x 400W mogel base MH set at 17 " above water

That seems a bit high. I run mine about 6" off the water, thinking of moving them up a couple inches, mostly to eliminate blasting the top corals, and giving myself a bit more room to work in tank without burning myself.
Keep us posted on SPS growth and color at that height!

lastlight · #3 02-09-2011, 03:49 PM

I'd move mine up if it were easy to do. I had to cut back my lighting bigtime as things were bleaching even under the 20k. I think I'll be going about 10" from surface to actual bulb in the new tank. I'm trying to puzzle out a nice way that each reflector can slide up or down into position within the canopy so they are easy to adjust for lighting and for access.

mike31154 · #4 02-09-2011, 04:03 PM

My 250w SE bulbs are about 8.5 inches from the water. They are in DIY Lumenarcs. I use plastic chain to suspend the fixture from the ceiling. This allows for relatively simple height adjustment by using a different chain link in the ceiling hook to raise or lower the assembly. Just need to make sure the chain is robust enough to handle the weight and so far so good for me. Might be able to rig up something similar inside a hood with a shorter length of chain. May not be as elegant a solution as an elaborate sliding or even automated rig, but on the plus side, it's simple, inexpensive and easy to set up.

I only have a couple of small SPS frags at the moment, so can't really provide any useful info as to growth. What I have is doing well. Down the road I'll definitely be looking at LED lighting to replace the MH.

Hangfire · #5 02-09-2011, 04:21 PM

I have one 250 Watt MH that's somewhere between 6 and 8 inches off the water surface. I have but one SPS that's probably only 8 to 12 inches under the water and it's doing great, so far.

Lampshade · #6 02-09-2011, 05:53 PM

I"m running 2x250W moguls about 8" above the water. SPS is doing great all different levels. I'm debating getting cheaper bulbs and adding a third ballast because it's a little too intense right now in some area's and i'm running out of shady room to put some not-as-high-light SPS.

StirCrazy · #7 02-09-2011, 06:05 PM

mine were 6" above the water.. that was the majority from that old poll if I remember that far back corectly.

is there a way you could put them on a slide inside so you could lift them when yuo have to be in there? well I am sure there is if there is room in the canopy. I might be able to give you an idea when I come down at the end of the month.

I had mine on drawer slides so they would slide out the end when I needed to work on the tank.

Steve