Looking for cheap soda lime for my CO2 scrubber

[dzhuo]

I installed a CO2 scrubber last night and it worked pretty well. My pH used to be 7.8 (as low as 7.6 has been observed) and tonight (after roughly 24 hours in use), the pH is holding steady in ~8.06 which is great. The problem is that 1/4 of the soda lime in the container is already purple.

I am looking for a cheaper way to refill the media. Any idea where I can purchase this stuff for bulk?

[dzhuo]

Sorry just to clarify when I say cheap soda lime, I really mean inexpensive; not that I am looking for inferior / cheaply made soda lime.

[Genetics]

Originally Posted by dzhuo

Sorry just to clarify when I say cheap soda lime, I really mean inexpensive; not that I am looking for inferior / cheaply made soda lime.

It shouldn't be hard to find it cheaply, especially if you look at the composition. Sorry I don't know where to find it though.

[dzhuo]

Is this skimmer media fine for the CO2 scrubber?

[dzhuo]

This website sells 3 lbs of soda lime for $7.50. Does anyone know it's good quality and can be used in CO2 scrubber?

[dzhuo]

No one?

[Boomer]

Is this skimmer media fine for the CO2 scrubber?

Yes, and about the best there is as I found it for him


Your other link is fine stuff also.


Do a Google search for " rebreather soda lime "

[teesquare]

Boomer - is it feasible to re-charge the soda-lime?
T

[dzhuo]

Originally Posted by Boomer

[b]Do a Google search for " rebreather soda lime "

Any chance you know where I can find the cheapest?

[Boomer]

Not really T, as


Ca(OH)2 (granular Kalk) + CO2 --- > CaCO3 Calcite solid ( think Aragonite), which is not an easy task to take say a coral skeleton and convert it back to Ca(OH)2 Kalk.


dz
http://northeastscubasupply.com/stor.../prod_617.html

$149.99 for 44lbs = $3.41 / lb and the link you posted is $2.50 / lb and that is really cheap

[dzhuo]

I have been using the soda lime from the link I posted for a few days now and it does seem to work. The weird thing is that the media stays white (and I know it didn't go through a reverse phrase from violet because I checked it twice a day. I would not have missed the reversal). The original media came with the CO2 scrubber turned to purple / violet in a matter of 3 days. If the soda lime I am currently using is the same grade, I would expect the same color changing to happen by now. In fact, it should be complete violet and should be discarded. I notice the pH has gone down from 8.06 to 7.96 now (night time) so I wonder:

1. If the media I got don't change color despite its claim.
2. If the media I got has a significantly longer absorbent capacity.
3. If the first batch of media (that came with the CO2 scrubber itself) has an incredibly low absorbent capacity. It only lasted about 4 days.

I also notice the link I posted above sells this soda lime in different shape. For example, BRS sells this media more or less in sphere shape while mine appear larger in size and like a cylinder as far as shape goes.

Any thoughts on this? I wonder if I should replace my media or buy from somewhere else.

[dzhuo]

Also, what about this media. Any good? What are the different grade means?

[saltywet]

Also, what about this media. Any good? What are the different grade means?

I have used the airgas sodalime. It worked really well for me. My PH with it was 8.2-8.4.

It starts running out in about 3 weeks where it changes color. My PH without sodalime is 7.9-8.1.

HTH

[dzhuo]

Did you order directly from airgas? If so, how much do you pay for? I sent them an email last night but haven't heard back yet.

[tmz]

It takes a week or two or three for mine to show any color change. The air gas product is fine, I use it. It came to about $90 for 5 gallons ( only size they carry) of it around 30lbs.They have locations throughout the country so if one is near you you can pick it up and save shipping. Don't think you can beat the 3 lbs fofr 7.50 though

[dzhuo]

The weird thing is the original media came with my CO2 scrubber exhausted in less than 7 days but this new one I use now hasn't shown any color change in a week. Obviously the CO2 concentration in the basement hasn't change much and air pull from my ATB is still roughly the same so I would have expected the media to at least show some purple which I am not seeing. Maybe I just wait a little longer and see how the pH react. I forget to check it this morning.

[Boomer]

There are a number of things to look at.

1. Moisture: Affects the media and lowers its capacity. You first batch may have dropped in capacity as it was pulling out to much moisture from the air ( but I do not buy into this). This should be less on the second batch refill. Basements are more of a good thing as they usually have higher humidity. Getting dried out, from storage or when used, as the air passes over it in the CO2 unit is the biggest concern as the media is suppose to have moisture to operate. Most are around 10 - 20 % moisture. Many companies have give a rather large range for their product, i.e., 12 - 18 % on at data sheet. Media moisture should be ~ 18 % and during operation the moisture should never get below 2 %. When I see these CO2 media with zeolites or adding water to the bottom of the canister it tells me one thing, the media is low in moisture to begin with.

2. Shape: Different shapes affect the adsorption capacity. It has been shown the cylinders are better than spherical or granular. Even manufactures that sell different grain shapes tell you that.

3. Grain size: This can get tricky as one does not what it to small or to big. Grains in the 8-12 ( 2.5 - 5 mm) mesh will last ~ 1.3 times longer than 4 - 8 mesh ( 1.0 - 2.5) or about 4 % more adsorption. But this is for re-breathers and IMHO 4-8 mesh is better for us. One issue here is the smaller the GS the greater the pressure drop. Something you do not want.

4. Grain porosity: Some media are more pours which gives more surface area and more or quicker adsorption.

5. Dust and Harness : You want about the lowest dust and highest hardness you can get.

For all practical purposes most are about same, i.e., there are no leaps and bound differences. Any media would have lost adsorption capacity in the first use if there are humidly problems in the basement.

The media sold by thefilterguys is about the best there its. It is # 1 in hospitals and re-breathers.

I'm one that does not believe in claims unless it is backed up by a data sheet. I have seen TFG data sheet on grain size/shape, moisture, adsorption capacity,etc.

[dzhuo]

Thx for the info Boomer. I will see what my pH tonight. Still haven't heard back from airgas.com yet.

[dzhuo]

Checked the pH and it's at 7.88 now so it seems like the media isn't doing much anymore. Time line wise, it's similar to what I see from the first batch original soda lime I got from BRS except the color doesn't change at all. I am going to change the media to see if pH goes back up. If it does, then it's pretty clear that these media does not change color (despite what the manufacturer claims).

[Boomer]

Yah, I would expect the media is shot with a pH like 7.88

[dzhuo]

I changed out the media today and notice they are in fact light purple. It's just very hard to see from the media container but once out, it's clearly changing color. The first batch I use just have a deeper purple so it's a lot easier to see. I put in a new batch tonight. With the rate I am going, I will need a lot of sodalime year long.

airgas called me today and said they are putting together an order for me. I am going to get 5lbs to test their stuff out.

[dzhuo]

airgas called again and they are actually putting together a 36lbs sodalime for me for $65. This comes out to less than $2 per lb. I am going to pick up the order next week (they happen to have a retail store 10 minutes from where I live). Let's see how their stuff works. The price definitely beats everything I have found so far by a large margin.

[Mike1918]

Originally Posted by dzhuo

airgas called again and they are actually putting together a 36lbs sodalime for me for $65. This comes out to less than $2 per lb. I am going to pick up the order next week (they happen to have a retail store 10 minutes from where I live). Let's see how their stuff works. The price definitely beats everything I have found so far by a large margin.

Any update? Just curious cause I am looking to purchase some soda lime. I was going to get the 3 lb. bag from shopmedvet.com but I also have an Airgas store close by.

[dzhuo]

I picked up the soda lime a couple of weeks ago from an Airgas office near where I live. The media works similar (as far as size and absorbing capacity goes) to the others I purchased from 2 other different companies. I plan to continue use their media for as long as I can (since they offer the best price).

My CO2 scrubber is able to keep my tank's pH between 8.0 and 8.2 without a problem.

[HiggyBrew]

For 4 years now my pH ranged from 7.78 - 8.10 in all 4 saltwater tanks, (my family must blow off a lot of CO2 in air tight house - I guess).

Last night I finally fired some BRS soda lime into my empty phos reactor, and then plugged the IN-280 skimmer air intake hose to the soda lime reactor output. The pH rose overnight from about 7.80 to 8.21! Usually my pH bottoms out overnight at 7.80 and stays there until the light come on, (despite constant kalkwasser drip while lights are out). I also pump in set amounts of CaCl2 and Na2CO3 throughout the day.

I will definitely be checking this thread regularly for the best deal on soda lime.

I may look into bringing in outside air to the skimmer to see if I can eliminate the need for the soda lime trick, but (knowing myself) this may take a while...