Question on article.

[jaden1]

Eric,
Your recent article compares some different lighting and filtration specs, I am wondering why tank 5 would not be at least growing rapidly if not producing daughters. Could the wavelength of the light not be condusive to this. I have read on sps threadss that 6500k mh bulbs produce the fastest sps growth. Though 10000k is not that far off. Just curious as to your further thoughts on this as I plan on putting 6500k mh bulbs inot my system. Thanks.

[michaelg]

I've seen rapid growth with 10K, 20K, and 6500K all in the same tank from bulb changes over the years.

[jaden1]

Yes I would agree that just about all bulbs produce growth rates that are more than acceptable, but the ushio 6500k bulb is the hands down growing winner from what I've read. Unfortunately this bulb does not come in a 175 watt bulb. I am probably going to go with a coralvue 6500 or 5500 k bulb. But my main interest here was why in the articles comparison did the tank with higher lumens per watt than all but 1 tank not produce any daughter colonies and only little coral growth. There must be more factors at play here than the ones listed. I would love to discuss it further, in an attempt to better understand lighting and filttration requirements of my corals. Oddly enough in my case the best growth I have had in any corals that I have kept was in a very low tech (no skimmer and poor lighting) tnak. NOw I was not keeping sps but did have a torch coral grow from scratch on a piece of live rock to over 27 heads in less than 2 years. During the same time period I kept several colonies of goniapora thriving. NOw that I have begun with sps everything I believed about this hobby has turned right side up on me. NOt convinced all this expensive equipment is really necessary or worth it. Just looking for some discussion.....

[michaelg]

I am working on increasing the n value from a lot of different tanks (though the water parameters will vary greatly here) just to see if there is a trend.

[EricHugo]

Michael, with all the frags you have and have distributed, it certainly would be interesting!

My answer is that I don't have an answer. I would suspect that my main tank has the most energy through both light and food. The others are trickier, and if I were to hazard a guess it would be variable energy budgets and a high degree of ability to acclimate to the best sources per tank.

[jaden1]

So even there relative placement within the different tanks could be affecting not only growth but the ability to reproduce. Which I beleive probably don't relate to each other anyhow.

[jaden1]

Also Eric I would liek to know what you think about something I was told on another thread; If I use the 6500k or 5500k bulb and have any extra nutrient load in my tank I am more likely to have an alfea problem than with say a 10k or 14k bulb. This didn't really make sense to me, but lighting is something I am only getting to know more fully now.

[EricHugo]

That does make sense...more irradiance, more algae. Also, plants seem to do better than corals with more of the non-bluish spectrum, but this could jsut be an artifact of the total irradiance that is greater in the lower K bulbs.

[jaden1]

Is the higher irradiance likely to cause more protective pigments in the corals to induce better color. I believe I read in your book that irradiance is one of the factors limiting coral coloration.

[michaelg]

I find them the same color no matter what tank I have had them in. Perhaps a little darker in the nanotank with PC lights.

[EricHugo]

agreed - I am not seeing any real shifts in color, only very subtle differences in pinkish brown. However, what you might see using fluorescence is a different story.

[michaelg]

Yes- and the lighting is sooo different between the 2 tanks, it is nay impossible to discern any real difference that might be there.