Fluorecent lamps for Chaetomorpha may not be optimal

[Randy Holmes-Farley]

Two comments relating to the growth of Chaetomorpha:

1. One of my refugia has a large ball of Chaetomorpha in it. I usually have to harvest huge wads of it every few weeks. It has been lit by normal incandescent track lighting in the past. 50-60 watt bulbs, either spot or flood.

About 6 weeks ago, when they burned out, I switched to some new fluorescent lamps that are the same shape as the old bulbs (par 30 maybe? some PAR number). I got them from Home Depot (I can get the actual info on them later).

OK, the punch line is that the Chaetomorpha has been hardly growing for the past 6 weeks, while the Caulerpa racemosa in my other refugium (lit as usual) has been growing much more than usual (winning the competition for nutrients).

Of course, it may have nothing to do with the lighting.

OR, perhaps the Chaetomorpha really needs or likes the redder lighting that comes from an incandescent lamp compared to a fluorescent lamp.


2. When I did my iodine experiemnts, I found that while Chaetomorpha grew quite rapidly under long fluorescent tubes, it grew fastest in the brightest lit spots, even though it was only a few inches under the tubes. Again, maybe not enough red unless the lighting is very bright???:

Anyway, I'll be switching back to incandescent bulbs and see what happens.

[Typhon]

Thanks..Randy .. Good to know..

[chewie]

Mine grows well under a single 30w T8 GE bulb, and it out grows C. Racemosa, as well as C. Mexicana.

Ever since I added the Chaetomorpha it has grown about 10 times faster than any Caulerpa I've had.

I gat a ziploc baggie full 2 months ago and have given away alot of it, but 2 days ago I harvested enough to fill a 5gal bucket half full.

I love this stuff!

[Gary Majchrzak]

Ditto your Chaetomorpha findings here, Randy. My Chaetomorpha originally struggled to compete with my Caulerpa. I swapped out my Sylvania fluorescent plant light for a 60 watt incandescent Phillips spot 'gro-light'. Chaetomorpha was able to then successfully compete with Caulerpa growing in the same area of my refugium. The growth rates of these two macroalgae remained fairly constant when I dosed Iron as well as when I dosed Iodine regularly: Chaeto would outcompete Caulerpa under the incandescent lighting.
At Tropicorium {Detroit} last weekend, Dick Perrin's employees were having a difficult time handling a HUGE mass of 'brillo pad' algae that grew in a vat in the greenhouse receiving sunlight.

[Plantbrain]

Make sure you give a few weeks for the algae to adjust to the new bulb color temps. 6000K down to 2500K is a big jump and the algae need a little time to adjust. Most algae/plants will adapt to whatever lighting provided in a fairly wide range.

Plants/algae have many methods for adapting to different light, some take milliseconds, some about month.

Watt for watt, the Quartz 12v DC GE color precise 50w bulbs produce good light/efficent for incads(17 lumes/watt).

This algae and most others will do well with most light if given time. New bulbs are often brighter. I stick with 5000-6700K lights for algae. 4100K color whites perform the same in test done recently as do the plant bulbs color temps (5000K-6500K bulbs). There was no significant difference.

The color to your eye is different and perception but as far as growth rates(5000-65000K looks nicer to most people), the lights should be similar if the intensity/other conditions are the same.
50w incad will only = about 7-10w NO FL as far as lumens.

Regards,
Tom Barr

[Randy Holmes-Farley]

Well, after 6 weeks, the Chaetomorpha is still not growing. That seems like enough time to me for them to adapt. Before that, it had grown nonstop for years.

This algae and most others will do well with most light if given time.

Have you seen any Chaetomorpha growth rate data comparisons for different bulbs?

The color to your eye is different and perception but as far as growth rates(5000-65000K looks nicer to most people), the lights should be similar if the intensity/other conditions are the same.

FWIW, I'm quite familiar with such lighting discussions. That's why I posted the result in the first place: it is different than what many have recently been taught to expect.

[Plantbrain]

Randy Holmes-Farley said:

" Well, after 6 weeks, the Chaetomorpha is still not growing. That seems like enough time to me for them to adapt. Before that, it had grown nonstop for years."

Consider this: adding new lighting, very likely more_ intensity_ would increase the rate of uptake, perhaps you might be out of something the algae needs, being a nutrient issue, not a lighting issue, the light intensity only drives the carbon and nutrient uptake rates(up/down to a point).
This alga is found in nature in the top meter or so. It would like all the red light I would think without much need for adapting to a different wavelength.

I liken light intesity to driving a car. The faster you go/the more light you have, the faster the uptake and faster a tank can crash/remove all the nutrients stunting growth(or slowing this alga down but favoring the larger C. racemosa).

The lower intensity incad lights likely balance your nutrient uptake needs for your system. Perhaps adding more light intensity depletes the water column and stunts the Chaetomorpha growth.

"Have you seen any Chaetomorpha growth rate data comparisons for different bulbs?"

Heck no:-)
But I'd read it if I see it.
Unless they can manage their nutrient levels and other factors well, it's often difficult to test for. I don't how many times I've seen folks attribute one thing to growth/algae infestation when it could be any number of things.
I've done my own alga work but not with this specific alga.

I have a way one can test for it.
A 4 ft tank can have a type of lighting on one 2ft side and another on the other 2 ft side and black porous divider in the middle. You can use whatever lighting you wish and this is convenient size.
I've done this with several species of FW algae and higher plants.
In every case the FL lighting worked as good. I used Quartz lighting and 150watts(3x50w) and the other side had 5000K FL lamps(2x20watts).

Then you need to get dry weights(for mg Carbon/day etc) for a growth rate or some other gauge like Chl a/per day etc.
Main issue for folks is getting the set up stable and maintaining the stability of the independent variables. That can be tough.

I found generally most plants do the same, most FW algae generally did as well(400/450nm and 600/650 nm and a 690nm).

But........some algae did better at different colors.
So it's possible this one likes the red color but the intensity issue is dogging this and the tank's previous nutrient levels are confounding things.

"FWIW, I'm quite familiar with such lighting discussions. That's why I posted the result in the first place: it is different than what many have recently been taught to expect."

I think you would need to compare the light intensities between the two light set ups to say much. Then try the wavelength issue/variables at similar intensities to get a handle on it. You may be right.

I think it's a balancing the light for the nutrient supply issue with your tank personally. Perhaps you just don't need that much light or else you need to add more nutrients for the alga to grow well. You can try to add approximately the same intensity with different color temps and see.

I'd be interested to see if the rates were better.

If you can divide the refugium in half with a lightproof piece with holes, attempt to guess/get the bulb lumens output data for each bulb you are using and eye ball or do wet weights for growth rates, I think if it is significant, you likely would see it. But you'll need to try different nutrient levels also. What is an optimal nutrient level for Chaetomorpha and Caulerpa with this lighting intensity?

Give it a shot(s). Would not cost much to do it either. Fair amount of work though

Regards,
Tom Barr

[Randy Holmes-Farley]

Consider this: adding new lighting, very likely more_ intensity_ would increase the rate of uptake, perhaps you might be out of something the algae needs, being a nutrient issue, not a lighting issue, the light intensity only drives the carbon and nutrient uptake rates(up/down to a point).

I don't know if it is brighter or not, but in a refugium that is down stream from this one, the Caulerpa racemosa on different lighting is growing more than usual. So the Chaetomorpha is not growing as much as it used to in relation to the Caulerpa in the same water. So if it is a limitation of some sort, it does not effect Caulerpa.

I've done this with several species of FW algae and higher plants.

FWIW, I done growth rate experiments on this species under fluorescent tube lights, but have not compared them to the incandescents that they normally grow under in my tank, nor the new fluorescent lamps that I am discussing in this thread. I agree that they grew fine under those lights with controlled (and elevated) nitrogen and phosphorus levels:

http://www.advancedaquarist.com/issu...l2003/chem.htm

[Eric Boerner]

Randy...

I am also having the same type of problem with my Chaeto. It too stopped growing at rampant rates about 2 months ago and doesn't seem like it is going to start up again. Within that time frame I have had a surge of hair algae and slight cyano. I have managed to curb the hair algae, yet some cyano remains.

I am still using the same twisted PC bulb I was using last year, when the algae was blooming at incredible rates.

I have also noticed that my Chaeto is a lot more brittle/fragile than it was several months ago. It used to be very long and stringy, but it is now very small condensed and breaks easy.

This colony of Chaeto is from a single ball source over a year ago.

The only real thing I can think that might attribute to the reduced growth rate would be maximized nutrient intake? Is it possible that a colony of macro algae, or Chaetomorpha in particular could get to a point where it just cannot absorb any more nutrients and quit growing? Could it be possible that the cell wall structure might have changed some how?

[Plantbrain]

I've mowed through a number of studies on Chaetomorpha(namely C. linum).
I did not find much with specific references to a particular spectrum of light. Most all researchers tend to go with micro Einstiens as a unit.
With deeper algae, phytoplankton, the measurements are done in the field and reproducing the same wavelength does not seem to be as important as the intensity to most studies.

I do not see why an alga would do better with a lower color temp and much less intensity unless it was a nutrient balance issue, not a color temp issue.

When you scale up the light intensity one would predict that nutrient uptake would also increase(up to a point but not likely with most lighting set ups we have).

If an incad light produces 1100 lumens at 75 watts and a 15 w FL light produces 1100 lumens, then you can compare the two fairly well.

But adding 5x the lighting will cause the alga to remove all the nutrients very fast. Basically starving itself. You can remedy this by reducing the light, removing some algae or dosing more nutrients/feeding the fish critters more often.

I really think this is a nutrient light balance issue and not one a preferred color spectrum.
It's a green algae like the Caulerpa, it has the same pigments and Chl as most higher plants and other green algae. The light harvesting complexes are not that different which is going to dictate the difference over one type of light wavelength vs another.

Can it use the energy available to it or not is the basic question.
If the FL's add 5x the energy vs the incad's, I fail to see where the wavelength issue will come into play as this is much more an observation of the intensity, not so much the color temp. All the energy will go down hill to P680 and P700 before being used to make ATP and NADPH. More would be lost at say 450 vs 650nm but not enough to make up for 5X and both algae have the ability to use either wavelength. FL lamps often shift to redder colors like MH's as they age and intensity drops to 70-90% in most cases over the bulb life.

Try dosing some nutrients or feeding more fish food etc to see if it improves things. Also, if you have a Lamott NO3 test kit or a Lamott/Hach PO4 kit, see the rate of uptake for one or both nutrients as you dose. That will be key and perhaps a bette rock to turn over than the lighting temp.

Try only one nutrient at a time for a week and test daily.
You can dose quite acurrately using KNO3 for the NO3(about +- 1ppm using teaspoons), PO4 is bit tougher to dose.
I've seen some rather rapid uptake rates in FW plants, 3-4ppm of NO3 removed and well over 0.3ppm of PO4 remove a day(some removed over 0.2ppm of PO4 in a few hours). Macro algae can do very well also.

NH4 from fish waste vs NO3 (long term waste that's been processed by bacteria) is a potential issue as well.

Generally I will not feed when I test for the PO4 or the NO3(a week run) due to this.

I'm still rearranging the tank so I'm not sure I can say much about the NO3/PO4 rates and I keep many species, not just a nice big monoculture of Chaetomorpha or Caluepa but even still, I think a general pattern of uptake rates when supplied with a consistent nutrient source will evolve for the macro algae and marine plants.

I'll report back when the tank is going well. I just added a number of new macro species and will wait till they are growing well and then start dosing NO3 first and then PO4.

Based on these two uptake rates, I'll combine them and see what happens. I know I'll have to control one of them pretty well when adding both.

Hope this helps and gives some ideas.
I'll be trying some stuff out myself but it'll be interesting to see anyone else gets similar results.
I'd be interested in the light incad vs the FL's but what types of lamps and brands are you using? We can look thos eup on line generally for lumen output. It's not as good as them little Einstiens but it's okay for this type of thing and all many of us might have. I have a Licor globe PAR meter and other light meters so I can test what I have here in terms of those units.

okay, I'll shut up now

Regards,
Tom Barr

[Randy Holmes-Farley]

But adding 5x the lighting will cause the alga to remove all the nutrients very fast. Basically starving itself. You can remedy this by reducing the light, removing some algae or dosing more nutrients/feeding the fish critters more often.

Are you talking about my situation, or Eric's?

That is not the explanation in my case, as I didn't significantly change the lighting intensity, just the spectrum. Additionally, the Caulerpa racemosa in a second refugium downstream from the Chaetomorpha was growing faster than usual, so nutritent limitation wasn't the issue.

In any case, I swapped out the fluorescent lamps for incandescents again, so we'll see what happens going forward.

[Randy Holmes-Farley]

Well, after a week under the incandescent spot lights (presently 2 x75 w), it is apparent that it is growing like gangbusters again.

[Mako]

This is all really interesting to me. I used Chaetomorpha exclusively in my fuge for about 1.5 years and it grew profusely under the 65k LOA's. Then all of sudden, around 5 or 6 months ago, it's growth rate went into what I would call a rapid decline.

I was extremely puzzled by this as nothing had really changed that I could pinpoint. Shortly after I noticed the same thing Eric was mentioning about the Chaeto becoming "brittle/fragile". Whereas before the strands were pretty tough, they would now break rather easily. This decline continued to the point where I could barely even grow the stuff.

Eventually, I had to resort to using different macro's in the fuge (i.e. calupera) which took off like a weed. I have recently acquired some more Chaeto (what little I had left eventually died off as the macros out did them) and I will try this batch in my sump under another LOA and see what transpires.

I really want to get this stuff going strong again as the macro's drive me nuts with their quirky sexual traits.

[Plantbrain]

I was referring to Randy's tank.
You are talking about intensity and not wattage?

150w of spot light at best has around 15 lumens per watt(less if not quartz/DC etc).
A 20 w NO FL light w/tar ballast has about 70 lumens per watt.

Incad=> 1500 lumens
FL=> 1400 lumens.

While a lumen is not the best unit, it's easy to find the info and at most spectrums this unit suffices when comparing intensity.

So is the old FL lamp that caused the issue around 15-20watts?

If not, I think it's difficult to say much about them being equal intensities. The other issue is light spread. A spot light will have a sweet spot.

But if the intensity is the same or close, and the nutrient supply is the same also, then you might have something.

I will say the difference between a 4000K vs a 6500K FL bulb are NOT significant concerning growth rates with most plants/algae. These are closer to the spread patterns, and the intensities that make comparing/isolating spectrums easier.

If you really want to answer the spectrum question, it might be better to try that. You can obtain low/high temp FL bulbs easily.

Regards,
Tom Barr

[Randy Holmes-Farley]

The details of the bulbs that I used (good and bad) are in this thread if anyone is interested:

http://archive.reefcentral.com/forum...56#post1678056

[horge]

Randy,

Got any clear pics of your weed that I can borrow?
I'm short on Chaeto pics.


Horge

[Randy Holmes-Farley]

It's not close, however.

[horge]

Hey, I'll still take it.



Thanks

[dc]

LOLm mines not doing well under any light.

[horge]

Debi... you again?
What camera are you using for those macros?

Can I filch those as well?

[dc]

LOL, Yea I show up every once in awhile. You may have the pics and I'm not sure which camera I used. Either a Kodak DC4800 with close up lens, or a Sony F717.

[elisabeth]

so i can assume that this is pretty much dead? i just got it
in the mail and i think the heat affected it. it's very brittle
and has all these beige 'spots' on it. Are those calcium?

i apologise for tagging along, but you folks seem to know the
subject matter

With Caulerpa prolifera, i noticed that when i first put it into
the refugium for the first time, it went great guns and then
slowed like soo many others have experienced. i wonder
if the nutrient limitation isn't some trace element? Because
all the usual suspects have to be readily available or
replenishable. And why else would just having a 'different
kind' of Macro seem to immediately take off where the
previous one slowed. I know this doesn't address light
spectrum but this has been something i've wondered
about ever since the first Macro-- C. prolifera slowed
3 years ago.

[TheMandarinFish]

I'm giving some chaetomorpha direct sunlight in my tank....

I just got it and will let you know how it works.

I think, and hope, my sunlit refugium is a real fortunate item.

I've considered adding light via a small regular flourescent during the dark cycle, too.

[CJ]

Originally posted by TheMandarinFish


I've considered adding light via a small regular flourescent during the dark cycle, too.

You won't have a dark cycle anymore then

[TheMandarinFish]

24 / 7 light in a refugium is supposed to help control PH swings, increase macro growth, and reduce the likelihood of caulerpa going sexual, correct?

Are there any downsides?