Bald Faced Newbie - Part I - Lighting

[jgpa]

I am brand spanking new into this money pit, I have all the usual questions. I am going to try to keep them segregated by topic instead of having all the varying advice subjects lumped into another newbie thread.

I can contribute - anyone have any chemistry questions, I have a degree. No, I am not a chemist, I have a degree and never used it professionally. There is a difference.

OK, my hobby has been seeded w/ a free 55G tank. My research and store browsing has led us to conclude we would like a nice soft coral reef tank with a few pretty fishies and some crustaceans and other inverts. I will seed the tank with some uncured LR and slowly build from there. I have assembled all the initial parts, am just awaiting the bucket of salt.

Knowing my goals above what lighting wavelengths are recommended? I have a total 260W (4x65W broad spectrum @ 6700 Kelvins). I suspect I will need to replace one or two?

Thanks.

[Kurt_Nelson]

With that lighting on a 55g, you'll do just fine with whatever soft corals and LPS corals you want. If those bulbs are of unknown age, I'd replace them all regardless of what type of bulbs you want. Personally, I'd replace them all and go with 2x 10,000K bulbs and 2x actinic (420nm or equal). With a reef tank, I think you'd prefer the whiter light of the 10,000K over the 6700K. But we've got plenty of lighting gurus that I'm sure will chime in soon! What light fixture is it?

Welcome aboard, and keep asking the questions. Sounds like you've done a fair bit of research already and that's a good thing. Especially like your comment "... and slowly build from there." Slow is a good thing too.

[Ziggy953]

I agree with Kurt, slow is good! Taking your time and researching everything before you make a move is a very smart way to play this game!

I would change the bulbs out also, and Kurts recomendation is a good one!

[jgpa]

Originally Posted by Kurt_Nelson

Personally, I'd replace them all and go with 2x 10,000K bulbs and 2x actinic (420nm or equal). With a reef tank, I think you'd prefer the whiter light of the 10,000K over the 6700K. But we've got plenty of lighting gurus that I'm sure will chime in soon! What light fixture is it?

Kurt, it is a new Coralife fixture, 48". I got the legs and a Lexan cover for it to sit on. As I understand the lighting, there are four criteria:

1) Proper wavelength for photosynthesis of the 'good guys'.

2) Proper wavelength to inhibit photosynthesis of the 'bad guys'.

3) Proper wavelength for purely visual appearance.

4) Intensity, to augment #1 and/or #3.

A LFP (local fish person), knowing the interest in soft corals, highly recommended this setup.

In terms of health and all that, would everything be OK with these wavelengths?

Maybe I can get established and then swap out for a pair of 420 nm's.

[ccCapt]

6700K is very close to sunlight and is a fine choice for soft coral. The only drawback is that K temp looks somewhat yellow. 10K bulbs are "whiter".

[cmor1701d]

Originally Posted by jgpa

I got the legs and a Lexan cover for it to sit on.

Is that a lexan cover for the top of the tank? If so consider removing it as the gas exchange take place at the water surface. Putting a cover on top the tank causes lowered pH.

[jgpa]

Originally Posted by cmor1701d

Is that a lexan cover for the top of the tank? If so consider removing it as the gas exchange take place at the water surface. Putting a cover on top the tank causes lowered pH.

How much of the surface can be covered? The store displays had all their coral tanks set up as such.

I'd need another way to support the fixture if I need to leave it open, I haven't actually had it out and fitted yet.

[Kurt_Nelson]

Originally Posted by jgpa

Kurt, it is a new Coralife fixture, 48". I got the legs and a Lexan cover for it to sit on. As I understand the lighting, there are four criteria:

1) Proper wavelength for photosynthesis of the 'good guys'.

2) Proper wavelength to inhibit photosynthesis of the 'bad guys'.

3) Proper wavelength for purely visual appearance.

4) Intensity, to augment #1 and/or #3.

A LFP (local fish person), knowing the interest in soft corals, highly recommended this setup.

In terms of health and all that, would everything be OK with these wavelengths?

Maybe I can get established and then swap out for a pair of 420 nm's.

Sounds like you've got a good grasp on lighting criteria! If it's a new fixture, then I'd probably be hesitant myself to throw out perfectly good bulbs too. CF bulbs, conservatively, like to be changed every 6 months - so maybe you're right... get started with what you have but switch out later down the road. I really think you'll like the whiter 10k K bulb, and once you get some fluorescent green LPS in there, you'll want the actinics. Seems like I read somewhere that nuisance algae prefer the lower wavelength "daylight" bulbs, but of course I can't find where I read that now.

How much of the surface can be covered? The store displays had all their coral tanks set up as such.

I'd need another way to support the fixture if I need to leave it open, I haven't actually had it out and fitted yet.

You said you had the legs for it, so why not just use those? I think we assumed from your comments that you're going to put the fixture right on the lexan cover. That's probably not a good idea, just due to the heat buildup. I know CF will easily break glass tops if set directly on top, so I'm sure they'll do a pretty good number to lexan also if set directly on it.

As far as covering the top of your tank, you just don't want a tight fitting cover that keeps you from getting good air exchange to the water's surface. Oxygenation of the water in a SW tank occurs at the surface, so if you seal it off good you risk the possibility of lowering the oxygen levels in your tank and lowering the pH.

[melosu58]

Moved to General Hardware and equipment discussion.

[jgpa]

Originally Posted by Kurt_Nelson

You said you had the legs for it, so why not just use those?

With no covers at all on the tank, there is very little surface upon which to perch the light. I just went and actually looked at the bits and not only do the legs fit on the tank top edges, the fixture lets you slide them back and forth. I was thinking there were fixed and just sat there.

So the lid serves nothing then but as a splash guard it seems. And keeps jumpers in.

Originally Posted by Kurt_Nelson

As far as covering the top of your tank, you just don't want a tight fitting cover that keeps you from getting good air exchange to the water's surface. Oxygenation of the water in a SW tank occurs at the surface, so if you seal it off good you risk the possibility of lowering the oxygen levels in your tank and lowering the pH.

I'm going to start a water thread, involving this item.

Thanks for the time.