Use of Lasers in Controlling Pest Algae and Corals

[dcforester1]

And I thought it was cool when I found out I could use ice melt to raise my calcium. What will they think of next?

 

[mussel and hate]

The laser allows pinpoint precision eradication. It's a practical remedy for pests nestled in with non-target sessile animals.

Certainly appropriate precautions should be observed. I believe a ~1 watt laser can be used safely. This thing isn't as dangerous as a submersible heater, or say a 75volt DC PSU. Either of the aforementioned can kill you outright if you don't treat them with respect.

I think the best practices document is an excellent idea and although I haven't a high powered laser I've played around with a laser pointer to test the reflective hazzard and it is very real.

I'd like to offer a suggestion regarding some reflection protection. An opaque plastic pipe just a bit larger in diameter than the laser host functions as an effective baffle when pressed to the glass with the laser inserted within. This should eliminate bounces off the front pane at least.

[*]As I understand it, a laser focuses light energy up to 100,000 times, thus the 1800mW laser being utilized is the equivalent of up to ~180,000 watts of energy being delivered to the pin-point focus point.

I don't think that's an accurate description of the laser's power. You've still only got 1.8W of energy but it's so finely focused that the tiny point of incidence can't dissipate the energy by conduction and so it burns. It's just like how you can burn yourself with the point of a 15W soldering iron more easily than with a higher wattage T12 NO fluorescent tube.

 

[CalmSeasQuest]

I don't think that's an accurate description of the laser's power. You've still only got 1.8W of energy but it's so finely focused that the tiny point of incidence can't dissipate the energy by conduction and so it burns. It's just like how you can burn yourself with the point of a 15W soldering iron more easily than with a higher wattage T12 NO fluorescent tube.

In rereading it the excerpt, it seems like we mostly agree, I was just trying to use a very simplistic explanation - Here's that section in its entirety...

"As I understand it, a laser focuses light energy up to 100,000 times, thus the 1800mW laser being utilized is the equivalent of up to ~180,000 watts of energy being delivered to the pin-point focus point. The energy is so focused, you can completely "vaporize" an Aiptasia polyp nestled in the middle of a desirable colony with little or no damage to corals in the immediate area (assuming your hand is steady enough.) All that said, we're still dealing with only 1.8 watts of energy.

In tests with the 1800mW laser, the focus point is critical. If not focused to a pinpoint, the effectiveness drops off sharply.

 

[TheFishMan65]

We used laser for a while in our office. We were told to keep the room lights on. I thnk the idea was to keep the iris closed as much as possible to limit the mount of light entering form the impact point EVEN WITH LASER SAFETY GLASSES.

I don't know if this will help. And maybe someone can verify. I purchaesed two pair of safety glasses so I could have an observer. Well if I shine the laser throught one some of the light (445 nm) is transmitted. Should I be looking for a new pair? Most (I woulld say) is reflected. What is interesting is that I had some red plexiglass/acrylice/something that actually refects (as near as I can tell) all light. So perhaps the red whatever can be a good barrier, but it may also cause more problems becuase of reflection. If you want more info (becuase you think it will help) on the red plexi let me know.

 

[CalmSeasQuest]

We used laser for a while in our office. We were told to keep the room lights on. I thnk the idea was to keep the iris closed as much as possible to limit the mount of light entering form the impact point EVEN WITH LASER SAFETY GLASSES..

Great input, every little bit helps (and it makes it easier to see and work .) With lower power lasers such as those used in laser pointers, your blink reflex is supposed to kick in before damage occurs to your eye. With these, a blink is too late. One concern - I want to be careful about suggesting anything that might be misinterpreted as to prompt a reader/user to skip any of the safeguards.

I don't know if this will help. And maybe someone can verify. I purchased two pair of safety glasses so I could have an observer. Well if I shine the laser throughout one some of the light (445 nm) is transmitted. Should I be looking for a new pair? Most (I would say) is reflected. What is interesting is that I had some red plexiglass/acrylice/something that actually refects (as near as I can tell) all light. So perhaps the red whatever can be a good barrier, but it may also cause more problems becuase of reflection. If you want more info (becuase you think it will help) on the red plexi let me know.

I've seen similar questions regarding the safety glasses, but haven't seen a clear answer. It would "seem" that some of the output nm laser light must be allowed to pass though the safety glasses, or we wouldn't be able to see the beam endpoint. I would be concerned if the performance between two identical glasses were markedly different. I'd inquire with the retailer or manufacturer.

My concern about the red plexi is, it might be that you can't "see" the beam penetrate, but significant laser energy is still passing through at potentially dangerous levels. The fact that my hand was "stung" by light I could not see while wearing the proper safety glasses suggests we have to be careful in making any recommendations. It seems the ideal would be either blocking the light entirely with solid or opaque materials, or using only the materials specifically designed to block the nm laser being used. I'm currently researching the best material and colors for the endpoint shielding (it will vary based on the spectrum laser being used.) I'm hoping I can find a supplier for the same material used in the safety glasses that manufactures other shapes - ideally, small diameter pipe.

 

[BluScrnOdeth]

ahhhhh, my eyes, the video, ahhh danger danger, lol, just be cautious with it. Its like people driving, you will have idiots that wreck and didnt buckle up to save their life, and those who did buckle up and survive. Proper protection if only found out through planning and experimenting. Theres a safe way, we will find it.

 

[BluScrnOdeth]

How about this. Totally safe way, may damage the camera over time, but thats the price you pay.

But get a PVC tube, put an end cap on it, drill a hole dead center and another off center, maybe 3 holes with 2 off center. Mount the lazer to the center hole and a camera/camera&light combo to the other holes. Turn on the light so you can see what you are pointing at on a small LCD screen and zap away with not blinging anything ot you getting zapped. You could even put something like a crosshare with a hole in the center bottom of it to better align where your lazer is shooing so you arent pointing your lazer in there and zapping your corals neat the target trying to align the lazer to your target.

 

[CalmSeasQuest]

There has been some discussion about lasers potentially posing a risk to acrylic tanks. An owner of a laser cutting shop issued a warning that they use lasers to cut acrylic.

I am not concerned about this for several reasons,

• I've been testing lasers on both glass and acrylic tanks with an 1800mW 445nm laser (the highest power output laser used so far in these applications) and have noted no damage or temperature rise whatsoever.
  
• Even if there was some initial temp increase (which I do not beleive), the cooling effect of water flowing over the materials surface would seemingly minimize it.
  
• There is a significant difference between our visible light lasers and the IR lasers designed for cutting (not to mention <2 watts vs 150 watts.)
  
• I posted these concerns in the LaserPointerForum - To date, no concerns were expressed and comment was made that the IR laser is designed for cutting acrylic.
  
• Lastly, but perhaps most importantly - jrpark22000 conducted testing using an IR thermometer on both glass and acrylic and determined there was no increase in temperature during use of the laser.

I've also ordered an IR thermometer to be able to do some additional testing including,

• Temperature rise at the beam endpoint
• Temperature rise in the areas immediately surrounding the target
• Effect on colored surface such as black acrylic or painted backgrounds
• Effect on joints (either silicone or fused acrylic.) Due to increased opacity, some laser energy may be absorbed thus caution should be maintained to avoid impacting any joints or seams.
• Impact of water flow on beam endpoint temperatures

My most significant concern are the joints and seams. While it's unlikely that anyone would intentionally attempt to laser through a corner or seam as it wouldnt be effective - there is the possibility of reflections doing so.

More research is needed to determine if this is a valid concern and if so, any long term effects.

 

[TheFishMan65]

One concern - I want to be careful about suggesting anything that might be misinterpreted as to prompt a reader/user to skip any of the safeguards.

What I was thinking (and maybe didn't explain well) is that even with glasses the spot is pretty darn bright and an awful lot of light enters the eye. While the glasses are supposed to make it save, why not be extra safe and let the eye naturally block some of that light. I expect most folks are doing this with the fish lights on and maybe that is all you should say.

My concern about the red plexi is, it might be that you can't "see" the beam penetrate, but significant laser energy is still passing through at potentially dangerous levels.

It is my understanding with the blue 445 all the energy is in the 445 range. So if you can't see any light coming through the it is either reflected or absorbed. The 532 green can in the UV band (maybe that is infrared) where you can't see it. That is why I stayed away from green when I got mine. I don't know if any other colors have a secondary spectrum.

 

[CreatiVe2]

There is an article written about this (gj calmsea)

http://www.advancedaquarist.com/blog/zap-aiptasia-dead-with-laser-beams

 

[CalmSeasQuest]

It's great to see Advanced Aquarist covering our work with Lasers.

In addition to simply "making things quickly go away" I think lasers can/will be helpful in other marine endeavours. I'm currently working on a few videos focusing on,

Preventing coral battles and potentially limiting allelopathy - The laser is perfectly suited for maintaining margins or a "DMZ" between potentially battling corals. As many of us (guilty as charged) end up with many SPS in tight quarters, a laser can be used to help prune back infringing corals with surgical accuracy without having to remove the coral, or risk damage through traditional pruning methods. I'll be using some fast growing Monties and Acros for these tests.

Prepping areas for regrowth - With corals subject to receding tissue, the exposed skeletons quickly become covered in various types of algae (no doubt due to the nutrients from the decaying coral.) I've tested using the laser to "scrub" those areas, hopefully creating a host surface that will aid in the coral regrowth. At first glance, it works very well, and the targeted surfaces are squeaky clean. Its especially effective at cleaning deeply grooved skeletons such as Acanthastrea. If successful, I can see potential benefit in the use on high value chalice corals. Time will tell if it provides any benefit to the coral in terms of speeding recovery.

Prepping areas prior to affixing a frag or coral - It's very simply to use the laser to prep an area before affixing a frag (either on a plug or directly.) In just seconds, and areas can be lased removing any potential pests or nuisance algae, and at least in theory - providing a better place for the coral to adhere to and encrust.

I'm also curious to see if laser "etching" of frag plugs results in any difference in coral growth or rates of encrusting. There are many others areas to explore including laser fragging of soft corals and whether the cauterization effect is beneficial,

Time will tell if any of these provide real benefit, or are just seemingly good ideas that don't work...And of course, I've also got the prerequisite Xenia, GSP, Aiptasia and Majano videos under development for those focusing solely on pest vaporization.

 

[CalmSeasQuest]

I completed a brief series of videos showing the eradication of Aiptasia, GSP and Xenia along with the cutting of a "DMZ" between battling Montipora.

I'll post them as soon as the uploads are processed by YouTube.

 

[CalmSeasQuest]

Here are a few short videos (HD) showing how different corals respond to the laser. The Montipora were lasered through glass - the rest through acrylic.

<iframe width="853" height="480" src="http://www.youtube.com/embed/QWnfnc_IdEo?hd=1" frameborder="0" allowfullscreen></iframe>

<iframe width="853" height="480" src="http://www.youtube.com/embed/AvPltwSOZDc?hd=1" frameborder="0" allowfullscreen></iframe>

<iframe width="853" height="480" src="http://www.youtube.com/embed/9dkux_JpPg4?hd=1" frameborder="0" allowfullscreen></iframe>

<iframe width="853" height="480" src="http://www.youtube.com/embed/Jky0U2MlPwk?hd=1" frameborder="0" allowfullscreen></iframe>

 

[CreatiVe2]

Awesome. Great post!

 

[BuckeyeTodd]

Has anyone gone deeper than 12" in the tank, and if so what laser was used? Due to cube layout most of mine are 18" from glass.

 

[jrpark22000]

I completed a brief series of videos showing the eradication of Aiptasia, GSP and Xenia along with the cutting of a "DMZ" between battling Montipora.

I'll post them as soon as the uploads are processed by YouTube.

If you would, please post back some results after a few days or weeks on the GSP, xenia, and monti.

I lased a xenia patch with similar looking results. A couple days later it needed a second treatment, I had to lase it to a pile of gelatinous goo to kill it. I am still waiting to see if the stalk base will grow a new head.

 

[CalmSeasQuest]

Awesome. Great post!

Thanks - Lot's more to do, but it's a start.

Has anyone gone deeper than 12" in the tank, and if so what laser was used? Due to cube layout most of mine are 18" from glass.

I've effectively lased target about 20" from the tank exterior and noticed no power falloff. That said, I'm using an 1800mW laser. Results will likely vary with lower power units.

If you would, please post back some results after a few days or weeks on the GSP, xenia, and monti.

I lased a xenia patch with similar looking results. A couple days later it needed a second treatment, I had to lase it to a pile of gelatinous goo to kill it. I am still waiting to see if the stalk base will grow a new head.

I'm following a number of tests, including Xenia. I agree it seems to be among the most laser-resistant and I suspect it might be associated with it's lighter color and greater mass. I've found that in smaller patches, I'm able to completely destroy it in a single session, with larger groupings requiring multiple laser sessions.

The Monti test was perfect...

It vaporized all the tissue in the lased area without hurting any of the surrounding polyps or tissue. All that remains is the bleached with skeleton.

Here are a few thoughts I've formulated since starting these tests...

• More is Better - Although expensive and requiring the maximum safety precautions, I think using lasers with the highest outputs are a plus. This is also important as it appears that many lasers being sold often fail to meet the advertised output. Better retailers will also provide (for a fee) a "power certificate" detailing the actual performance of the laser and diode being purchased.
  
• Cooling effect of water requires higher power output - Because were using laser to superheat and destroy pest with the aquarium, were subject to the cooling effect of the surrounding, moving water.
  
• Planula - One of the primary pest being targeted is Aiptasia. When attacked, it can release free-swimming larva called Planula. If not destroyed, these can go on to create many hundreds (if not thousands) of new pests. In theory at least, we want to generate the maximum heat possible, in the shortest time possible to destroy any Planula released.
  
• Transparency and colors resistant to laser - Some of the pests being tested seem more resistant to destruction by laser. These include Xenia, a much lighter (almost white colored) soft coral that is very fleshy and seems to recover from even extended lase sessions.
  
• Use in destroying blue/green algaes - Many algaes also seem resistant to laser destruction. While the sizzling and popping sounds are easily heard during lasering - they seemingly are able to regrow.

While 1800mw 445nm is proving to be extremely effective, I'm currently researching the use of a different spectrum laser that might provide even better results over the 445. More to follow...

 

[redreef85]

Very interesting

 

[BuckeyeTodd]

Does anyone else find it amazing that due to our love of saltwater fish, we have now learned advanced plumbing, introductory electrical, acrylic fabrication, advanced biology, and now lasers.

 

[CalmSeasQuest]

Does anyone else find it amazing that due to our love of saltwater fish, we have now learned advanced plumbing, introductory electrical, acrylic fabrication, advanced biology, and now lasers.

Not to mention chemistry, mechanical engineering, physics including fluid dynamics, HVAC...

We've come a long way from that fresh water tank that used to sit on our bedroom dresser