Use of Lasers in Controlling Pest Algae and Corals

[BluScrnOdeth]

and no comment on what i suggested would make this completely safe.....

 

[CalmSeasQuest]

and no comment on what i suggested would make this completely safe.....

Darin,

Thanks for your input. Although I'm not sure I completely understand your post, it does not appear to address exposure to the beam endpoint.

I think the important take away here is I don't beleive it's possible to make this process "completely safe" with any single device. It requires a series of safety practices, most of which are human-elements as opposed to equipment.

 

[BluScrnOdeth]

there is no exposure to the beams endpoint by you, the tube would be wide enough to capture andy reflective light. The cross hair (draw an X and put a circle in the center, earase the inside of the circle) thats the endoint where the laser would shoot through. Get that pont really close to your target, the close, the less of a change of stray rays.

 

[TheFishMan65]

I guess you are assuming a water proof laser. The other problem is that most of the laser look like the focus ring is near the front. I think that maybe the biggest obstacle to over come for safety. Short of soldering something to the focus ring I have not thought of any good ideas.

 

[BluScrnOdeth]

Not really, i was thinking you would have a long tube, which is why you would have a light for inside the tube, this way you can keep the light and the LCD display out of the water. It makes it more cluncky than just pointing a laser into water while getting a tan, but, if safety is import then this would be a good solution, but not easy. I dont expect anyone to use/make this, but it would completely shelter you from the rays except for any that shoot out at about 180 degrees.

 

[CalmSeasQuest]

I guess you are assuming a water proof laser. The other problem is that most of the laser look like the focus ring is near the front. I think that maybe the biggest obstacle to over come for safety. Short of soldering something to the focus ring I have not thought of any good ideas.

A waterproof host is an option, there are some out there, but I'm with you, I'd be also be leery of the focus ring. I'm assuming they are fixed focus and I'm not sure how effective they would be for this purpose.

I've been working on an idea being initially discussed and being furthered by CJ. Creating a "conduit" that when lasing from above the tank, would shield the beam and all endpoint viewing angles, except those of the user.

I'm using Mylar sheeting, rolled into cone shape that will burn through when lasered directly in air, is seemingly cooled enough by the water to prevent burning (at least in my testing so far with 1800mW of 445nm.) In addition, any laser striking the Mylar in actual use would be glancing, likely unfocused and would largely be reflected thereby imparting much less energy.

Wrap the end of the laser in the Mylar on an angle so a cone shape is produced. This provides a larger area to shield the beam endpoint and minimized the chance of the beam striking the walls of the cone.

A bit of tape secures the cone and affixes it to the laser (the taped section does not get wet.)

I cut out a section of the end of the cone allowing easy viewing (by the user) of the beam endpoint while shielding all other angles. This cut-out also allows air to escape making it more stable and easier to stay "on-target".

It's still too early to say if this will be a viable option. I do note that while it works, I don't get as "clean" and endpoint when shooting through the surface vs. shooting through the tank walls. This is likely due to reflections from the surface of the water.

It's a bit clunky, but does appear to provide protection benefits in a simple and inexpensive manner including,

• Protection from livestock seeing or potentially crossing the beam
• Protection from viewing the beam endpoint from most angles
• Elimination of most reflection risks

Time and more testing will tell...

 

[CalmSeasQuest]

In trying to determine the best (and safest) methods for the use of lasers, I'm not sure 445nm is the best wavelength for this application. It looks like 405nm has a couple of significant benefits namely the ability to focus to a much finer endpoint (445nm endpoint is actually a line rather than a dot.) This further concentrates the cutting/burning power while requiring much less power output.

It appears that a 405nm running at 900mW would be as effective as a 445nm at 1800mW. This would be safer and more cost effective.

I'm working on obtaining a 405nm build now - testing to follow...

 

[CalmSeasQuest]

For anyone questioning the potential damage a 1000mW laser can do - Here's a story about a laser hobbyist inadvertently struck in the eye by a 1 watt 445 nm, blue laser (less powerful than what many are using in aquaria.) Even though the laser struck his eye for only about a second (as it rolled off a table), it resulted in burns to his retina requiring surgery (at the time time this was written, the outcome of surgery was still pending.)

To give you a sense of the damage to his eye - Here's an image of a healthy retina...

Here's the image of the retina damaged by the laser...

Had he been wearing appropriate eye protection, no damage would have resulted.

 

[CJO]

That's scary!

CJ

 

[TheFishMan65]

CalmSeaQuest, you know a lot more than me, but I don't know the glasses would have protected him. Glasses are safe for looking at the spot created on a non reflective surface. I am not sure they would block a full on laser hit. They might have helped, but I think there would still be damage. I am only trying to clarify as I don't want people to think that glasses are the whole answer.

 

[billsreef]

Really makes one wonder about the wisdom of playing with lasers, when there are other safer methods available.

 

[Yogre]

Really makes one wonder about the wisdom of playing with lasers, when there are other safer methods available.

Randy had the same point earlier in this thread. In an instant an individual's life was permanently altered.

I understand that life is not risk-free, but there are risks worth taking and others, not so much.

I won't be using any lasers in my tank. I'm not afraid of them, but for me the risk/reward ratio just isn't right.

 

[jrpark22000]

Topic suggestion to add to the best pratice sheet;
"What to do if an accident occurs"
subtopic; research local treatment before operating laser.

I was unable to find a complete nationwide listing for the U.S., but a quick google search provided me the results for my local area.

 

[hvacman250]

Maybe I've missed the answer in all the laser threads Ive read, but what are these powerful lasers used for (outside of aquaria ), and why are they so easy to acquire?

 

[CalmSeasQuest]

CalmSeaQuest, you know a lot more than me, but I don't know the glasses would have protected him. Glasses are safe for looking at the spot created on a non reflective surface. I am not sure they would block a full on laser hit. They might have helped, but I think there would still be damage. I am only trying to clarify as I don't want people to think that glasses are the whole answer.

I agree that laser safety requires more than just safety glasses. In this case, the user failed to secure a live laser, allowing it to fall off a table resulting in the eye strike.

As for my comment that glasses would have protected the user in this case - It's based on the following,

Although all safety glasses warn against direct viewing, a good quality pair of safety glasses such as pair of Eagle Pair 190-540nm are rated OD 4+ (reduce the intensity of 190-540nm laser light by a factor of 10,000 or more) The 1watt 445nm laser output would have been reduced to no more than .1mW.

Here's test of a set of Eagle Pair glasses vs a 2000mW 445nm laser (DOUBLE the power of the laser that inflicted the eye injury) demonstrating that the Eagle Pair lenses reduced the laser to less than .1mW (the laser power meter actually reads zero) and would have protected the user from any eye damage from a brief exposure. This would NOT work for an extended period of time as eventually the glasses would heat and potentially melt.

That said, obviously no one should EVER allow a laser beam to strike their eye, regardless of any eye protection.

 

[CalmSeasQuest]

Really makes one wonder about the wisdom of playing with lasers, when there are other safer methods available.

Randy had the same point earlier in this thread. In an instant an individual's life was permanently altered.

I understand that life is not risk-free, but there are risks worth taking and others, not so much.

I won't be using any lasers in my tank. I'm not afraid of them, but for me the risk/reward ratio just isn't right.

Both certainly are valid points and everyone has to determine if the use of lasers are good choice in their situation.

By design, I've made it a point to include (highlight) the risks associated with failing to follow laser safety precautions - not becasue I beleive lasers to be a bad idea, but rather to "alert" those new to lasers into paying attention to the very real dangers and safety risks.

The single greatest risk is to your eyes (and potentially those of your livestock.) Using appropriate eye protection is an easy safety precaution to take, all but eliminating any risk to your vision whatsoever. A comparison might be to that of a welder using an arc shield. You simply MUST use adequate eye protection.

When used in a safe manner, I've found lasers to be an effective and surgically accurate way to manage certain pests in marine aquaria.

 

[Sk8r]

Seems to me that someone setting up an "I'll come to your house with my laser and take out your aiptasia" type business after getting himself insured and bonded, and taking expert precautions, including barring everyone from the room, might be better than people getting one of these things and going through a very, very dangerous learning curve.

 

[CalmSeasQuest]

Seems to me that someone setting up an "I'll come to your house with my laser and take out your aiptasia" type business after getting himself insured and bonded, and taking expert precautions, including barring everyone from the room, might be better than people getting one of these things and going through a very, very dangerous learning curve.

I've thought the same Sk8r - Maybe a nice additional service offering for service/maintenance companies (although I can just imagine the conversation with the insurance underwriter - "you want to do what???")

In reality, it's really not that complex, it's just that there are significant risk of bodily injury if the safety requirements are ignored.

 

[dimitrge]

From what Ive read you can't just buy them. Then i see them on ebay and reading in other threads you can get them from laser forums.

 

[TheFishMan65]

It is my understanding that it is illegal to sell a laser above some number of watts, but you can sell the parts or a kit. That is the way you need to look for them.