Help me decide on lights. Tank dimensions are 84x24x30 deep. Right now just running 3x6ft vho bulbs on Fowlr. I'd like to step into t5s and keep soft coral. Can I get away with two 4 bulb 36 " fixtures? Or do I need more light? And what bulb configuration would you do? Thanks a lot!
Wow that sounds like a nice tank roughly 260 gallons. But with the 7' dimension your just short of being able to use 2 48" slight or slightly long for 2 36" lights. From your note on wanting to keep soft corals which are fairly light forgiving however if your like 80% of the people you will eventualy want to step up to at least LPS corals that need more light.
If you can suspend a fixture overhead than I would initially go with a 48" 8 bulb fixture that will give you loads of light in the center but you will have fall out on the ends. This will give you more than enough light to keep your softies on the ends and yet in the center you can actualy go with basicly anything you want.
If the fall out on the ends turns out unexcaptable you do have that tank lenght where you can add additional fixtures on each side perpenduclar to your main light in the future to help you around the fall out issue on the ends.
The aproach I'm using is to help you avoid what I have seen so often n the business. Individuals try to save a $ by buying the least expensive lights that will make there present needs but do not plan ahead. They basickly start with a $250 light to keep just fish, than a year larter decide they want some live rock and softies so get a $500 fixture. Than next year they decise they want SPS corals and have to buy another $700 fixture. In reality they invested $1450 in lights over a 2 year period where they could have gotten away with spending $700 initialy.
Just looking at some quality fixtures 2, 6 bulb 36" fixtures would set you back roughly $1,100 and for 8 bulb fixtures $1,400. all at once. But with the 48" 6 bulbs will cost you under $650 and 8 bulbs will cost you about $800.00. With the savings of about $500 you can later go with two less expensive 4 bulb 24" fixtures for close to what your saving now.
the big difference being if you want to spend the money now or spend it in the future? For many people it is easier to spend the $800 now and the added $600 a year from now than spending $1,400 now. But either the two 36" lights or the single 48" light will alow you keep your soft corals now.