Will running almost only blues give me less par?

I have two current usa marine orbit led fixtures. I like the look of having my blues on 100% in the evening but I run the white at 15% during the day. If I were to only run the blues, would I be missing out on a lot of par? I want to get good coral growth, right now I have softies, zoas, lps, and one sps. What should I run the lights at to provide the best balance of physical looks and actual light intensity?

By the way I have a 29 gallon tank if that makes a difference

 

Bump!

Thanks!

Ken

 

Blue is a more important spectrum. Blue is what penetrates the water. It is true blue will have a lower PAR but the white while having a higher PAR will lack PUR... Are you manually controlling these units? Personally if they're not controllable I would go 70% for both blues and 20% whites and 7-9 hours and don't mess around with ramping it unless you want to look at corals under all actinic blue.

 

So if I just have my actinics on I won't get as much growth? I can put the whites on during the day for better growth, but I really love how the corals pop under the actinics

 

Most corals actually do significantly better under low light situation that is fully covered. You really never want to put whites on above 20-30% and they're not needed more than 4hr a day.

Even acropora can THRIVE in low light conditions if they're stable with high Ca, kH, and Mg with good flow to provide the elements and oxygen to the polyps. However even in low flow sitution acro will grow. Just less thick and tight but more thin and branchy and wavy. Contrary to popular belief the intensity of light is not as important as the spectrum and coverage and angles of light.

But algae will always grow quicker under spectrums closer to the 6.5K spectrum. The corals really grow and color better under the UV spectrum above 15k. They really drop in growth at the 20k by like 25% but the overall color of growth is far superior in my opinion.

Your call, quicker growth vs lack of color I guess.

The algae within the corals do not actually need much light to live and the flourecent properties of corals show better and grow better colorations under actinic

You have heard of people just burning corals... Light acclimation over weeks to a month is important for corals used to less light. And the best looking more colorful are typically grown in extreme low light haha

 

I'm just confused about how to equate wavelength to color temperature. You said that corals grow and color better between 15-20k I can reduce the whites to 4 hours per day but will the dual actinics provide what the corals need to thrive as far as light goes? I will focus highly on my water parameters and flow but I want to make sure that the lighting isn't my weakest link. I want a balance between viewing pleasure and coral growth

 

Like I said most corals don't need much light believe it or not haha.

You may consider acclimating them to less light for better coloration. The double actinic would be fine most likely.

 

My Acropora tank is a 22k Metal Halide (Actinic is 20k) and I have two True Actinic 20K ATI. The corals look better with all actinic lighting. It effects growth though...

 

I think I will just run the dual daylight LEDs for 4 hours per day and the dual actinics for the rest of the time the lights are on and see how it works with my corals

 

why can't you run them together?

 

I was going to run them both for 4 hours in the middle of the cycle and the actinics the rest of the time.

 

I have turned the whites on for most of the day at 20%. Is white light necessary for coral growth or is blue mostly what they use since the white light is filtered out in saltwater at certain depths

 

Light absorption by Zooxanthellae peaks in the 420-450 range (UV, Royal Blue) and again in the 660-680 range (red). However keep in mind these are just the peaks, there are other wavelengths being used which is why most people have gone "full spectrum" to cover the space between the peaks. White lights tend to supplement the blue because the whites will contains some of the 660-680nm peaks, like a warm white will give you even more red than a cool white. That's why you see the early LED fixtures using simply whites and royal blues, the two wavelength peaks for coral photosynthesis. The blues are usually more important and that's why a simple white can get you by for the red peaks instead of an actual red LED. Of course in the full spectrum fixtures you get both and all colors of the rainbow.

I have my whites turned down on my fixture, in my small tank the whites penetrate the water so much that I can't run them full strength. I would keep doing what you are doing and see what happens. Over time I would very slowly increase the whites to just give more overall light for growth. Talking real slow too, don't shock them.

This of course is a very broad explanation as this is a deep subject that could be really dug into if you wanted to like how Chlorophyll A works with Carotenoids and their absorption of light spectrum and how it all ties into coral growth.

 

I will just keep doing what I'm doing. I guess this is the patience part haha
I really don't want to buy a par meter

 

No you really don't lol $$$. The corals will usually visually tell you what's going on in the tank. Patience is the name of the game in saltwater.

 

My sps have improved in the last month or so. I added more but even the ones that were looking rough when I got them and doing well now

 

I would like to build my own led fixture so that I can make full spectrum with plenty of par

 

When it comes to LED, it's more than just par ratings and this is where many of us fail to see the difference from conventional lighting to LED. We tend to think watts and PAR which has it's place with LED but what we really need to be sure of is the PUR ratings as well, Sure, lots of choices but you really need to research for your needs. The current units and others are low to mid range in terms of LED. I own the Current Sat Plus and recently after issues have flipped to the TMC GroBeam which for one is not made in China, has a better warranty and delivers true PUR. Here's an article on LED that goes much more into the details of LED lighting and their spectrums.



PUR vs PAR


Building your own is possible with quality components and that's the real key, using inferior quality will result in light for sure, but not the type of light you may wish for.

Corals from what I've read need more than just blue, UV(Purple) and other light spectrums are also widely used for salt water setups.

I for one firmly believe IMO that using ramp up/down sequencing adds to a healthier bio-sphere which I tested in a freshwater 55G aquascape and once I added the RT I began to see even more interactions from my community. Yes it's a few bucks more, but the level of light induced stress is not only normalized, but becomes more natural and beneficial for anything living. As I've said before, same effect if you sleep in a dark closet and someone flips the light on.

 

Good to know! Thanks. I really want one that has a full spectrum and I love the ramping timer on mine

 

Good to know! Thanks. I really want one that has a full spectrum and I love the ramping timer on mine

For freshwater or saltwater as there is a bit of difference.

Saltwater makes use of the extra colors just the way nature gives in the real world. Certain colors may not reach as deep but don't rule them out as even green plays a role in photosynthesis and colors of both corals and fish.

There is a great post here and in particular, the explanation given by the poster ReeferMadness which lays it out for all to understand.