Lighting Quandry

[GunnerO]

I'VE GOT A 75 GAL MTTHAT 20 INCHES DEEP, THAT PRESENTLY HAS A CURRENT FLORESCENT FIXTURE WITH 230W OUTPUT. I HAVE SOME FISH , LPS AND SOFTIES BECAUSE OF THE LIGHT OUTPUT.

WOULD A 692 MH/ FLORESCENT FIXTURE( 2-250W &2-96W ACTNIC) BE TOO MUCH FOR THESE CORALS TO HANDLE OR ADJUST TOO? CAN THE MH BULBS BE SWITCHED TO 175W WITH ANY PROBLEM?

ALL SUGGESTIONS, HELP WOULD BE APPRECIATED.

[aquainas]

Eventually they would all adjust you would have to limit the photoperiod to a few hours each day for a couple weeks. You could also hang the light over the tank at a good distance to decrease intensity and run a somewhat normal light cycle, also with a 20" tank on 250w halide you would definitely be able to grow sps( if you choose). I wouldn't recommend running a 175w bulb on a 250w ballast.

[bnumair]

Hey guys i am new at this hobby.
i been reading alot on lighting. i have a 120 gal reef tank.
48longx24tallx24deep.
i have about 80lbs of LR and 3 inch black and white fine grain live sand mixed togather to give it like an ASH look.
i have 2 true clowns 2 clarkii 2 powder blue tangs 1 yellow 1 naso tang 1 blue hippo.
on corals i have green star polyps lots of mushrooms, soft leathers devil fingers, frog sprawn and some others that i dont know about.
my question is i have 8x55w T5 HO 50/50 lights on a 12 hours timer 10am to 10pm and moonlight 24 hrs.
it s got 2 fixtures.
1. is coralife 4x55w PC 50/50
2. is Odyssea 4x55w T5 HO lamps also 50/50
is this too much light?
Is 12 hrs daylight 50/50 enough?
moonlight runs 24hrs it that ok?
thanks to everyone for helping.

[aquainas]

I woudn't say you have too much light...but I would recommend 8-10 hrs max at full light.

With an 8 bulb setup such as yours you could use timers to mimic dawn, midday and dusk. Shoot for something like: 2 actinics only from 7-9, have 2 daylights come on in addition to the first 2 actinics till ~12, have all bulbs turn on from 12-5, turn off the first 2 daylights and actinics at 5 leaving the second set of daylight and actinics on until about 7 then turn the last 2 daylights off leaving your last set of actinics stay on till ~10pm for viewing.

The second set of actinics could actually be 50/50's which you already have, this way you have a bit more light for viewing at light. It's quite simple really, however if we began discussing the different spectrum and manufacturers of bulbs it could get a bit confusing. Let me know if this all makes sense.

[aquainas]

Sorry for the typos...I'm replying from my G1

[bnumair]

thank you aquainas
that was very informational. i had something similar in mind.
great help thanks.
one more thing.
the moonlight leds should i leave them on 24 hrs?
all lights go off at 10pm and moonlight leds stay on 24 hrs.
or should i cut those off too later on like midnight or 2-3 in the morning, actanics come on at 630am.

[aquainas]

Glad to help!

You do not have to turn the moonlights off at all. It's been argued that coral benefit from them so leave em on, unless you feel the need to have them shut off during daylight.