MCU Research CO2 Scrubber

[gasman059]

Boomer thx I bet ya the articles are quite conflicting- and furthermore w/o even reviewing the article and reference, childrens anesthesia has tons of variables the must important of all is the different circuits utilized and the possiblity of re-breathing that each circiut brings to the table.
There's Mapleson A-B-D( types of circuits) etc and all to some extent can casue re- breathing if not utilized at a certain flow rates.

Who would have thought i would be getting anesthesia CME'S in reefcentral LOL.


While there's always a possibility of re-breathing with low flow states( meaning utilizing a flowmeter with a fresh gas flow of oxygen below 1 in must cases) our anesthesia machines do provide us alarms to avoid this problem.

The reference to rats as it related to this forum was specific to sevoflurane and seviflurane only and it causes renal faliure when they are exposed to low flow states for prolongued periods of anesthesia/sevoflurane.

Sevoflurane anesthesia is used every x millions around our O.R> w/o problems. Is safe with a great partition coeficient and a proven track record.


Our vapors are quite safe this days and our anesthesia machines even safer---some have changed since I went to medical school/anesthesia residency and so forth but for the must part our avoidance of re-breathing whether it is with soda lime/baralime in a closed or semiopen circuits is completely dependent on our ability to be vigilant and the used of soda/baralime.

 

[Boomer]

Thanks gas for the further input

Who would have thought i would be getting anesthesia CME'S in reefcentral

:rollface::rollface::rollface:

I'll go back to my cave on chem issues I know about before I start post-hole digging myself, with an Anesthesiologist, in his own field

 

[Yogre]

Yeah, you guys are making my head hurt. :lolspin:

I'm going to hook up a system soon, I'll post my results as well. Although, I don't have a controller so I can't post any graphs. As I mentioned earlier in the thread, I've struggled from the get-go with low(er) pH due to a tight house and not being able to keep the windows open much of the year.

Great thread as always here in the chem forum! :thumbsup:

 

[Boomer]

Take 2 of these and lie down for 1 hr

 

[addicted2reefin]

Boomer, in ur post u stated u need to reach a ph of 10.something to have zero co2. u have it backwards. if u have zero co2 u reach a ph of 10. u cannot manipulate co2 by adjusting alkalinity and ph, but co2 adjusts ph. and this is based on no other buffers in the water other than carbonates and co2. im sure u knew this just thought i would clarify this for the rest

 

[Boomer]

I think your are very confused Where do you come up with "backwards". If you take a sample of water and add some CO2 the pH will go down with no effect on Alk. If you take a sample of water and remove the Alk it will have not effect on CO2. If you take a sample of water and add a buffer to it the Alk and CO2 will both increase and in many cases so will the pH.

Here is my post

In regards to your pH. As Randy has stated yes it can get to high. You will see this in heavy planted aquariums, be it FW or SW, where the pH can it over 9 pH. And all from what, the Algae or plants pulling out the CO2 just like the scrubber or limewater. @ 25 C, 35 ppt, 2.5 meq / l Alk, a pH of ~ 10.5 must be reached to have zero CO2

None of what you claim is there in that post. Nowhere am I trying to manipulate anything. And where do you come up with this pH of 10 ? At a pH of 10 in the parameters I gave the CO2 = .0007 ppm and at a pH of 10.5 = .0001 and to be exact at a pH of 10.58 it is zero CO2 and this ~ = About and I said ~(about) 10.5. How do I get this From a seawater CO2 calculator, set to Salinity, Temp, pK1 and pK2 @ atm, taken from Luecker et al., 2000. And in FW it is a pH of 10.92

I forgot, if I subtract for Borate Alk the pH is 10.55

http://www.hamzasreef.com/Contents/Calculators/CO2LevelSalt.htm Look in the lower right corner for credit

Just thought I would clarify this for all the readers

 

[Young Frankenstein]

I am more interested in the graph and that PH controller, anyone else using that to get great charts like that one ?

 

[gasman059]

Thanks gas for the further input

Who would have thought i would be getting anesthesia CME'S in reefcentral

:rollface::rollface::rollface:

I'll go back to my cave on chem issues I know about before I start post-hole digging myself, with an Anesthesiologist, in his own field

:beer:

BTW I would also like those fancy graph posts.

 

[addicted2reefin]

ok, i wasnt saying that u were manipulating anything, and i said ph of about 10, cuz i didnt know it was 10.5 or whatever u said.

the only way to effect co2 in anything is to add or subtract co2. i know u are reffering to the kh, ph, co2 charts and alot of people get confused in planted tank with this. they figure that if the ph goes down, then co2 must go up, and they get all confused and add abunch of ph down. well this isnt the case, they are adding another chemical which nullifies the table. if u raise the ph to 10.5 u could still have co2 in the water. this is all i am trying to say, not argue or degrade ur statement at all, sorry if it came off that way. depending on the buffer it may increase/decrase co2, if it will form carbonic acid with the water. kalk binds up the carbon dropping co2 and raising alk, and ph.

if u raise ph with a foreign substance, co2 will stay the same. if u drop ph, co2 will stay the same, at a given alk. i was reffering to this "a ph of 10.5 must be reached to have zero co2". i am just debating that u could raise the ph to 10.5 and still have co2 in the water, u are making it seem that if u raise the ph, co2 drops. it is backwards because u must drop co2 to zero to have a ph of 10.5 at the given alk with no other buffers.

 

[Boomer]

I'm not confused at all but you still are very, very confused. If you add a buffer, like baking Soda, the Alk goes up, as does the CO2 and the pH can remain the same but depending variables it can also up or down. Meaning, the pH can go down with an increase in CO2 if you raise the Alk by adding buffer but usually as the CO2 is blown off it raises the pH a tad.

The pH and CO2 dictate the Alk. The Alk and CO2 dictate the pH. The Alk and pH dictate the CO2. If you know the pH and Alk you can calculate the CO2. If you known the CO2 and Alk you can calculate the pH. And if you know the CO2 and pH you can calculate the Alk. Adding buffer affects all 3 of them. You are not going to have any CO2 in the water at a pH of 10.5 unless the Alk is very, very, high.

if u raise ph with a foreign substance, co2 will stay the same.

No it will not. If I add baking soda, a foreign substance, the Alk and CO2 will go up and the pH can be the same or could go down or up depending on some variables.

if u raise the ph to 10.5 u could still have co2 in the water

When you raise the pH of water the CO2 is converted Bicarbonate and Bicarbonate is converted to Carbonate. As the pH gets higher all the CO2 is converted to Bicarbonate and Carbonate and there is no CO2. As the pH continues to raise all the Bicarbonate is converted to Carbonate. If I take a sample of water and aerate hell out of it I will drive off all the C02 and the pH will go up and you just said it can't go up.

u are making it seem that if u raise the ph, co2 drops. it is backwards because u must drop co2 to zero to have a ph of 10.5 at the given alk with no other buffers.

It does drop as the pH rises. You seem to think if you have a pH of 8 with CO2 at 2 ppm and the pH rises to 8.5 the CO2 is the same. It is not the same, as the CO2 is converted to Bicarbonate as pH goes up.

CO2_g + H2O ==> H2CO3 + ==> HCO3- ==> CO3--

As the reaction moves from right to left the pH goes down. As it movers from left to right pH goes up

Here, in seawater at 35 ppt @ 25 C 1atm

pH 8, Alk 2.5 meq/ l = 0.9462 ppm CO2

pH 8.3, Alk 2.5 meq / l = 0.4188

pH 8.5 , Alk 2.5 meq / l = 0.2324

Now what is happening here, as the pH goes up, the CO2 drops. Now if we were to increase the Alk at the same rate of CO2 fall, as the pH goes up, the CO2 can remain the same.


pH 8, Alk 2.5 meq/ l = 0.946 ppm CO2

pH 8.3, Alk 5.67 meq / l = 0.946

pH 8.5 , Alk 10.18 meq / l = 0.946



You can also have a higher CO2 at a higher pH

pH 8.0, Alk 2.5 meq/ l = 0.946

pH 8.2, Alk 4.5 meq/ l = 0.997

This will give you a better idea what happens to CO2 as pH rises. Note the flat line for CO2 starting at a pH of around 9 and note how the bicarb and carb shift in their concentration. Note at a pH of ~ 6 it is half CO2 and half bicarb, with no carb and the note at a pH of ~ 9 it is half bicarb and half carb and about zero CO2.

they figure that if the ph goes down, then co2 must go up,

How is that, a FW CO2 table is pretty clear, as the pH goes down the CO2 increases.

Some things for you to read, if you can understand it

The Relationship Between Alkalinity and pH.
http://www.advancedaquarist.com/issues/may2002/chem.htm

What is Alkalinity
http://www.advancedaquarist.com/2002/2/chemistry

 

[euromomtx]

I just wanted to say THANKS for posting this thread. I've been thinking of getting the CO2 scrubber for awhile but didn't think I could afford the 30 bucks a pop for refills so the link to the filterguys was great.
I got my filterguys package and tried out the scrubber/media and now I am exactly where I want to be.
Before daily high/low: 7.7 to 8.25 (I did run an airline from skimmer intake to window)
After CO2 media added high/low: 7.8 to 8.35 Yay! (just CO2 scrubber, no more airline to the window )
And with the refillable cartridge the media only cost me $10 per refill

Thanks!

 

[Boomer]

Karin keep us updated on how long the media lasts

 

[porthios]

karin?

 

[euromomtx]

I replaced the media last week so that would have been a bit short of 1 month. I bet I did it too early though. It was just lightly purple.
I'm sorry but I am a terrible test person because I also changed other things around:
I got a bigger sump (from 20 gallon to 50 gallon) which seemed to have cut my swing from a 0.5 down to only 0.3 swing range. (I have a very large refugium on opposite to DT light cycle now)
I also am dosing a more saturated ATO of kalk.
In short I no longer struggle with low pH at all but I also did 3 things at once and can't say for sure how much each of these impacted this improvement.

 

[porthios]

awesome, ty

 

[gasman059]

so far so good in my system- media been running for about 2-3 weeks and all is well.
my next replacement will be medical grade soda lime that should last perhaps longer. I will report back my findings, if there's any improvement.