CO2 scrubber

[naprestsleep]

The idea is to lower the co2 in the air being used. You could use an air stone and pump on a scrubber but it's just as easy to install the scrubber on a skimmer.

[Gary Majchrzak]

have you increased the amount of media being run in order to further raise pH?

have you fine tuned your methodology at all?

[Gary Majchrzak]

Originally Posted by Blurry

great stuff! I love the idea, slightly concerned as to the repetitive costs. Looking at the $90/5 gallons compared to on-line prices does help. thereefguys are coming in at $54/gallon - that puts you at almost %70 lower!

please keep us posted! I'll probably jump on board as soon as there is more data on lifespan of the media.

I'm interested in lifepsan reports as well. I imagine they'll vary according to CO2 levels in different environments.

Also... has anyone in Rochester found a place to purchase this stuff?

[pascal32]

I've been running with a filterguys canister with media cartridge (about 1/6th of a gallon which is a little over 2 1/2 cups) seems to last about 3 weeks for me. I really should start keeping notes, I used to and stopped for no good reason other than laziness.

I can tell when the cartridge is running low by the PH. I usually replace when there is still a little bit of white left.

either of these stores in rochester should be able to get you bulk media. If you work for a company you might be able to get a discount on top of the already nice pricing

this falls under medical, so you might want to call the medical branch

Distance: 4 miles
Name: Airgas East
Phone: (866) 718-0685
Fax: (585) 254-4168
Address: 1144 Lexington Avenue,
Rochester, NY 14606
Facility Type(s): Retail Store
Get Directions

Distance: 8 miles
Name: Airgas East
Phone: (866) 718-0685
Fax: (585) 436-8907
Address: 77 Deep Rock Road,
Rochester, NY 14624
Facility Type(s): Fill Plant
Branch
Specialty Gas Lab - Regional
Medical Branch
ISO 9000
Retail Store
Get Directions

[Gary Majchrzak]

thanks for that info

[apt220]

This is a good thread and although I am not from your region, I found it after doing a search. I just want to share my soda lime consumption experience.

I used a CO2 scrubber for over month now on the intake of my skimmer. It really helped bring my pH up to 8.4 before the lights turn off and it would stay over ~8.26 by morning. Before the scrubber, my pH used to max out at about 8.1. I have a 100g with a 40g sump and I top off with kalkwasser.

I burned through the stuff pretty fast though. About 1.5 lbs for me lasted for six days which is when the pH wouldn't max out as high. I am one guy in a 1 bedroom apartment who is gone 9.5 hours per day for work with the windows closed 24/7.

[Gary Majchrzak]

thanks for sharing that. Looks like I'll go through a lot!

I might need to use "plan B": get rid of the rabbit and dog

[pascal32]

Originally Posted by apt220

This is a good thread and although I am not from your region, I found it after doing a search. I just want to share my soda lime consumption experience.

I used a CO2 scrubber for over month now on the intake of my skimmer. It really helped bring my pH up to 8.4 before the lights turn off and it would stay over ~8.26 by morning. Before the scrubber, my pH used to max out at about 8.1. I have a 100g with a 40g sump and I top off with kalkwasser.

I burned through the stuff pretty fast though. About 1.5 lbs for me lasted for six days which is when the pH wouldn't max out as high. I am one guy in a 1 bedroom apartment who is gone 9.5 hours per day for work with the windows closed 24/7.

wow - that's a lot. What kind of skimmer are you using? can you post a picture of how you have the scrubber set up?

I'm running about 1/6 th of a gallon every 3 weeks, so to give "safe" numbers, at this rate I would go through just over 4 gallons a year - so $6.60 a month at the full retail price.

Mine is set up like this:

[apt220]

Yeah seriously, I'm not sure why I go through so much so fast. Personally, I think I have a high baseline cellular metabolism. Also, I fidget a lot and I can eat lots of food and won't gain much weight. But anyway...

I run it essentially like you and the OP--just not as pretty. I just made the soda lime chamber out of those half-gallon containers at Walmart and drilled a bunch of holes in the bottom. I covered the bottom with the black sponge stuff and poured the soda lime on top. The skimmer pulls air from the top.

Here are some pics:









My skimmer is a reef octopus xp-2000 cone and it is a straight BEAST so I don't know if that is contributing to the fast consumption rate.

[pascal32]

wow, thats a lot of media. when it purples, how much is changing color? Is the color throughout, or does the air have a preference and only affect a small portion of the media?

I'm curious as I run a fraction of that amount and i still have spots which stay white which indicates the air has a path of least resistance. Could you try putting a "tube" in there from say a 20 oz soda bottle?

[apt220]

The color appears to change uniformly. It starts at the bottom and works it's way up--at least from what I can tell from the outside. I'm not sure what you mean by placing a tube in there.

I should probably be more specific when I say I go through 1.5 pounds every 6 days...
At about 3-4 days, the bottom 1/4 of the media is already light purple and I notice that the pH doesn't peak as high (maybe peaks to around 8.33 vs. 8.42ish with a new refill). Over the next couple of days, the purple progresses and the day/nighttime pH peaks/troughs are lower. I could probably stretch the media longer, but the pH peaks will drop each day.

[pascal32]

with the tube i was thinking of reducing the quantity of media you have, though I'm starting to think your skimmer just pulls a ton of air.

I just got the updated MyReef SW installed, so i don't have any graphs. we'll have to wait two weeks, just replaced the media yesterday and set the graph today.

[Kent E]

I think the concept is a good one... if... the source of high co2 in the tank isn't caused by high co2 in the house. In my particular case the whole house co2 increased significantly every winter as the ph dropped, and in the summer the ph wasn't as difficult to deal with.

A direct outdoor air source for the skimmer helped, but not as much as I needed. I'm venting the house now and ph is much higher and more stable. One would think the fresh air intake for the skimmer would be enough, but perhaps the house being high in co2 wasn't letting it escape out of the tank? ~I don't know.

How does one test whole house co2? I guess, Vent the house and see if that affects the tank PH.

I bring this up because if high whole house co2 is the cause of some people's low ph problems, they can vent the house solve their tank ph problems and have overall better air quality in their home.

If whole house co2 levels aren't the case, as I'm sure it's not in many situations, than this concept is very interesting and appears to work.

[Gary Majchrzak]

I'm positive that a "beast skimmer" will have an effect on how fast the media is depleted.

[tmz]

I've been off the boards for a few days. Sorry for the late response.

I'm getting 6 weeks out of about 2/3 of a liter in each of two scrubbers ,one on an asm 4x and one on an asm 4xx. Ph pre scrubber was 7.9 to 8.1 range . Now after about 3 weeks ph dips from 8.3/8.4 to 8.2/8.3 as some of the media purples up but it gets a deeper purple in the second 3 weeks and I'm ok with the 8.2/3 it maintains during the second 3 weeks. I think some of the ph boost may be related to the lower relative humidity in the basement at this time of year though.

[reefkeeper2]

One of Randys two part recipies call for heating baking soda in an oven for an hour or so to drive off the CO2. Could this media be regenerated by heating in an oven?

[Gary Majchrzak]

Originally Posted by reefkeeper2

One of Randys two part recipies call for heating baking soda in an oven for an hour or so to drive off the CO2. Could this media be regenerated by heating in an oven?

good question, Paul!

We need to find out...

Merry Christmas, BTW.

[reefkeeper2]

Thanks Gary. Merry Christmas to you too!
It would be great if we could regenerate this stuff. It made a huge difference with the ph of my tank.

[Gary Majchrzak]

*I had a discussion on this topic many many months ago*!

After reviewing the previous discussion that I had with several folks educated on this matter (among them Boomer, Randy Holmes-Farley, Brian Edwards, Ken Feldman, Craig Bingman, Sanjay etc. etc.) it appears that this media is NOT renewable "in the home".

What this means exactly.... I don't really know. It sounds like it might involve some special equipment but I'm just guessing. It also might be a way for those manufacturing the media to keep sales up.... if you know what I mean.
I'm going to have to go back to these guys and get them to elaborate.... if possible.

Apparently there are at least 3 different blends of media being marketed.
They perform slightly differently but performance of all may suffer if operating in a relative humidity under 40%.
(It's been suggested to add water to the reactor chamber if RH is under 40%)

Some generalized excerpts that I can provide (nothing groundbreaking here):
Soda lime is a Carbon Dioxide absorbent used for removal of CO2 mainly from breathable gases, in medical, military, safety and recreational applications. Each of these applications has differing parameters for use and therefore slightly different product make-ups. For example, medical gas is moisturized to a degree to aid in patient comfort, therefore soda lime used in anesthesia machines has a low moisture content. Additionally, the granules are lower on a hardness scale. Alternately, the granules of soda lime used in diving have a higher moisture content and hardness. The moisture content is important as a catalyst in the process.

Soda lime itself is not a catalyst; it is an absorbent which converts the carbon dioxide from a gas to a stable solid which is retained within the absorbent canister. It is possible to predict the capacity of a scrubber canister and therefore the life expectancy for a given set of conditions. Variations in the conditions can significantly affect the predicted life expectancy. Flow rate, CO2 concentration, temperature, pressure, humidity etc. are all examples of conditions that affect the life expectancy of soda lime.

Soda lime is contained in a scrubber canister, appropriately sized for the application. The gas is passed through the scrubber and the CO2 is removed by a base catalyzed chemical reaction, converting the CO2 to Calcium Carbonate. Once the soda lime is consumed, CO2 breakthrough will occur and the CO2 level in the exiting gas stream begins to increase.

Particle size and shape are particularly important in terms of the performance of scrubber material in its intended application. Most soda lime grades are now produced with shape that offers a high surface to volume ratio. These carefully engineered shapes ensure maximum CO2 penetration into the particles, by minimizing the distance to the centre of the particle, thereby increasing the CO2 capacity of the product. The hardness of the material is optimized to offer low-dust content, even after shipping and travel.

Another key factor in performance is the particle size distribution. Particle size has an effect on the speed of reaction, which in turn affects the volume of the reaction zone and the capacity of the scrubber. In general terms, the smaller the particle size, the faster the reaction and the smaller the reaction zone volume. However, the smaller the particle size, the greater the pressure-drop across the scrubber, which may affect work of breathing and other characteristics.

The question has been put forth. Looks like one might need a kiln and 850 Celsius. We'll see what the experts say.................

[Gary Majchrzak]

one cannot renew the media.

Tom- one thing that I just plain don't understand is how CO2 levels outside could almost be the same as those found in a tightly closed up dwelling (house). Is it really NOT worth tapping outside air for my skimmer intake?

[pascal32]

While you are waiting for Tom to chime in, re-enforcing your statement - pre-sodalime I took some tank water outside and aerated it for 60 minutes and the PH didn't change - yet the sodalime makes a notable difference.

[Gary Majchrzak]

thanks for posting your experience, B.
I got myself a reactor chamber today: a big wide mouth plastic Utz pretzal container. Now I just need to find some sodalime- hopefully locally.
I've got quite a shopping list!

[tmz]

Hi Gary,
The inside outside aeration ph test will tell you if it's worth it to bring in outside air which may/may not contain less CO2 than your house air. In any case it will contain some(388ppm CO2 in the atmosphere). The CO2 scrubber should purge it out to near 0 ppm,I believe.

[SaraB]

Just found this thread and I think I'm going to give this a try here in the future. I've had lower ph even though my fishroom has been been vented to outside air in the winter. I typically run around the 7.7 level. It had risen when I was dosing 2-part manually but now that I have my CA reactor online it's back down in the high 7's. I also run a Kalk reactor on my system for top-off but that has not helped me over the last 4 years for levels.

My question is I run a "beast" of a skimmer with 2 pumps so I have 2 air intake lines. Should I just start out with 1 line on a CO2 scrubber and see how my ph reacts? I'm guessing yes, but I rather be safe than sorry.

[pascal32]

Seems that starting with one is good for acclimation reasons. the PH will go up pretty quickly! I acclimated mine by putting an airlin T in place full open and closing it a bit every day.

If you skimmer pulls a lot of air you should consider buying in bulk (5 gallons at airgas) as you might go through the media quicker than most.

for the double, you can share the same reactor, just make sure it can handle the flow. that way you only have one reactor to monitor and replace media in.