I am looking at getting an Optima Fx. my main concern is the availability of the extend air cartrige in out of the way destinations. i am a working instructor, and not sure where i will end up next, but its likely to not be the states. on the farrallon site, i saw a reference to a cartrige insert to allow the use of granular sorb. i was wondering if anyone knows anything about this.or any other possible mods. of course id use the extend air if available, but it would be nice to have the option.
Optima and granular sorb
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SFLDiver3445
Contributor
I've been diving my Optima for a couple of years now, and live 5 minutes away from Dive Rite Express, which is where I was trained. I'm also part of a very active group of rebreather divers in South Florida, which includes plenty of Optimas, and I'm also very active on Rebreather World, and communicate on its message boards with Optima divers all over the country/world.
I've never heard of any available adapter for using granular sorb in their Optima, and I also have not heard of anyone personally modifying their unit in order to use granular sorb. Could you post a link to the site that you indicate has an adapter for this use?
I like the ease of use, the consitency and the safety benefits that come with using the EAC. However, the EACs can be more expensive to use and they can be difficult to acquire in some locations, especially out of the country.
Consequently, if I were in the market for a rebreather today, and I was uncertain about what part of the world I would be based out of in the near future, I would definitely not be purchasing an Optima.
However, even with another brand of rebreather, in many places, there's a good chance you are still going to have difficulty acquiring cells, O2 and sorb.
Adrian
Just me but if I'm not in the water I like for my cassettes to be vertically oriented so any settling happens in a direction that would be helpful, it would be hard to do that in an optima. I've also never heard of it done either, probably a sin of some sort
As was already mentioned, Optima might not be the best bet if you don't know where you'll end up. "Out of the way" places have "out of the way" issues. On one extreme there is Curt Bowen who dives a KISS with no onboard tanks or wing because of out of the way issues...don't know if I'd go that far but you need to really consider which unit you could fix in the field with what you have in the field.
As was already mentioned, Optima might not be the best bet if you don't know where you'll end up. "Out of the way" places have "out of the way" issues. On one extreme there is Curt Bowen who dives a KISS with no onboard tanks or wing because of out of the way issues...don't know if I'd go that far but you need to really consider which unit you could fix in the field with what you have in the field.
Dsix36
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If I read your post on the other forum correctly, then you have already purchased an Optima. The availability of EAC's in remote locations may be an issue, but you can always have DGE (Mark) ship them to you. Make sure to have plently of consumables and repair parts on hand.
Like Adrian said, we live right around the corner and can get anything we need in a matter of minutes, but on the other side of the world you will need to be prepared.
Like Adrian said, we live right around the corner and can get anything we need in a matter of minutes, but on the other side of the world you will need to be prepared.
Granular adapter for the Optima is most likely not going to happen.
It is not a simple as dropping in an EAC shaped adapter. The entire flow characteristics of the loop need to be re-designed. Not an easy task, and certainly not cost effective for Dive Rite, or an aftermarket manufacturer. Plus the EAC was chosen specifically, as Lamar wanted to reduce the possibilities of caustic cocktails.
It is not a simple as dropping in an EAC shaped adapter. The entire flow characteristics of the loop need to be re-designed. Not an easy task, and certainly not cost effective for Dive Rite, or an aftermarket manufacturer. Plus the EAC was chosen specifically, as Lamar wanted to reduce the possibilities of caustic cocktails.
Gill Envy
Contributor
I was told years ago, when I first became enamored with the optima that an adapter prototype existed and would be available "soon" to the market. I didn't trust this information and it was one of the deal breakers for me not getting an optima. three years later and still no adapter.
I buy my granular sorb in bulk, change it out often without having to worry about saving money ... my operating costs of consumables is around that of diving nitrox per hour. The EAC is expensive and bulky... granular is compact and easily shipped/taken with and it's really not much of a bother to use. It would be nice to have the choice between the two.. I like choices but having to choose one, i'd go with a rebreather that takes granular any day.
g
I buy my granular sorb in bulk, change it out often without having to worry about saving money ... my operating costs of consumables is around that of diving nitrox per hour. The EAC is expensive and bulky... granular is compact and easily shipped/taken with and it's really not much of a bother to use. It would be nice to have the choice between the two.. I like choices but having to choose one, i'd go with a rebreather that takes granular any day.
g
The cost of the EAC is not significantly more than granular though it will be somewhat more most of the time. There are some benefits that go with the added expense.
For example, the EAC takes just a few seconds to load on a rocking boat. Less hassle for live aboard dive trips.
The EAC packs consistently time after time, giving the same result time after time. Packing granular sorb is "an art," as the description has been said by Jeff Bozanic in Understanding Rebreathers (also sold under the title Mastering Rebreathers). Ask ten people how hard to pack in the scrubber when they pack granular. You are likely to get at least three variations of the answer from the group: Hard like cement, medium firm, and just enough not to hear shifting after closing the lid. They can't all be right.
By weight, the EAC absorbs more CO2 than does the same amount of granular. So, if you are traveling with EACs, you can carry less weight for the given number of hours of diving. This can offset the added cost of the EACs especially when the airlines are charging for overweight luggage as they are these days.
Regarding the difficulty of traveling with EACs compared to granular, I just came back from CCR cave diving in Mexico. I brought my EACs with me on the flight without issue.
There are definitely places in the world where getting EACs is more difficult than granular sorb. If that is an issue for you, you should look for a CCR that uses granular. On the other hand, if you can get EACs locally, or have them shipped to your destination, or can bring them with you, the Optima would be a great rebreather to consider.
Gill Envy
Contributor
Thanks for the reply Howard. I can see that there are some advantages but the last time I checked it out it was more than double the cost of sodasorb... that's assuming you buy the granular in bulk, compared to full price for the EAC.
how much are you getting the EAC's for these days? are there bulk purchase options? can they be recycled? do you "pack them in and pack them out" when diving in remote locations? The synthetic base material is non-biodegradable, right?
g
A month or so ago EAC's were running $150-$160 per case of 4, or in other words, about $40 each. That is still close to twice the cost of sorb bought in bulk.
There are people buying in bulk. However, even assuming that you are paying the retail price, an EAC is rated to scrub 240 liters of carbon dioxide. Assuming production of one liter per minute, that comes to 240 minutes, or four hours. Even at $40 per EAC, that comes to ten dollars per hour.
Anyone who is spending the money that it takes to get a rebreather in the first place is likely to be able to spend $10 per hour for scrubber. So, if you are only spending half of this but are risking things like caustic dust from sorb powder that makes its way to your mouth, I am willing to pay a few bucks more to eliminate this risk.
Second, if you are changing from open circuit diving, where you were paying sometimes more than $125 in Trimix for filling a set of doubles for a single dive, and you are now paying perhaps $30 for about four dives worth of Trimix and oxygen in your CCR tanks, I am not going to be overly concerned about paying an extra $5 per hour for operating cost. My primary concern lies elsewhere such as ease of use, tolerance to water contact, and low work of breathing.
There is a small amount of plastic in each EAC that will not biodegrade. I have been told that there is a very small plastic mesh to which the carbon dioxide absorbant is molecularly bonded in each EAC. (However, I have not personally seen the fabrication process.) This is one disadvantage that I wish would change.
I definitely want to see less plastic going into landfills. Plastic is basically forever. :depressed:
If by packing in and out, you mean carrying to remote locations on my back, then I can't say that I have had this pleasure. (Sherpas, anyone?
) However, there is no reason that it can't be done. You just have to make sure to adequately protect the units from crusing during transit. Again, each EAC weighs only 4.4 pounds. So, the weight is reasonable for the duration.
Anyone who is spending the money that it takes to get a rebreather in the first place is likely to be able to spend $10 per hour for scrubber. So, if you are only spending half of this but are risking things like caustic dust from sorb powder that makes its way to your mouth, I am willing to pay a few bucks more to eliminate this risk.
Second, if you are changing from open circuit diving, where you were paying sometimes more than $125 in Trimix for filling a set of doubles for a single dive, and you are now paying perhaps $30 for about four dives worth of Trimix and oxygen in your CCR tanks, I am not going to be overly concerned about paying an extra $5 per hour for operating cost. My primary concern lies elsewhere such as ease of use, tolerance to water contact, and low work of breathing.
There is a small amount of plastic in each EAC that will not biodegrade. I have been told that there is a very small plastic mesh to which the carbon dioxide absorbant is molecularly bonded in each EAC. (However, I have not personally seen the fabrication process.) This is one disadvantage that I wish would change.
I definitely want to see less plastic going into landfills. Plastic is basically forever. :depressed:If by packing in and out, you mean carrying to remote locations on my back, then I can't say that I have had this pleasure. (Sherpas, anyone?
) However, there is no reason that it can't be done. You just have to make sure to adequately protect the units from crusing during transit. Again, each EAC weighs only 4.4 pounds. So, the weight is reasonable for the duration.Similar threads
