fresh air from outdoors to raise pH
- Thread starter Gary Majchrzak
- Start date
I like the idea of fresh air for the system paricularly since mine is in the basement near the workshop but how fresh is it? I'd have some concerns about where to put the intake, certainly not near areas where I might in a numb brained state spray weeds or bugs.
Gary, maybe th beckett venturi responds to air pressure changes in a less sensitive way(sucks harder) than the asm needle wheel set up.With the asm there was a definate fall of in bubble production. The hose I used was also 3/8 inches.
Gary, maybe th beckett venturi responds to air pressure changes in a less sensitive way(sucks harder) than the asm needle wheel set up.With the asm there was a definate fall of in bubble production. The hose I used was also 3/8 inches.
SkiFletch
New member
Gary, the pressure drop in 3/8" tubing is SIGNIFICANTLY lower over longer lengths than typical airline tubing of 3/16" or 1/4" diameter. The relationship of tube ID to pressure drop (per foot) is NOT linear. Its something more like logrithmic or exponential. So as your diameter gets smaller, the pressure drop will increase drastically. 3/8" is right around the "breaking point" for air at moderate flowrates, so it doesn't surprise me that this has worked well for you 
Gary Majchrzak
Team RC
I think we're all in agreement here- in fact, I was wondering what kind of effect a 25' 3/8" diameter hose would have on a needlewheel skimmer and Tom just answered that
My Beckett sucks hard. She's like an old 396 V8... raw muscle! There's no doubt it's working close to optimal. Maybe someday I'll get an airflow meter on 'er and find out exactly what type of pressure drop I'm getting from the long intake hose.
Without tweaking my pH probe I've gone from 7.14 to 7.63 but there are several other variables involved- four houseguests have left and I did a water change.
The bottom line is everything in the aquarium is looking better now and I don't have to entertain in-laws
My Beckett sucks hard. She's like an old 396 V8... raw muscle! There's no doubt it's working close to optimal. Maybe someday I'll get an airflow meter on 'er and find out exactly what type of pressure drop I'm getting from the long intake hose.
Without tweaking my pH probe I've gone from 7.14 to 7.63 but there are several other variables involved- four houseguests have left and I did a water change.
The bottom line is everything in the aquarium is looking better now and I don't have to entertain in-laws
Gary Majchrzak
Team RC
I suspect that I need to recalibrate the probe, Tom. I'm willing to bet dollars to donuts it's actually above 7.8
Gary Majchrzak
Team RC
thanks for suggesting that Tom
oceanparadise1
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josh.vince
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jelly
chrisqueenz
New member
Boston creme filled..
Gary Majchrzak
Team RC
slowly but surely pH is rising
slowly but surely pH is rising
without any other changes the probe is indicating pH 7.7 right now
slowly but surely pH is rising
without any other changes the probe is indicating pH 7.7 right now
jansenwrasse
New member
I didn't see where tom posted this, but if you plan to remove CO2 what are you planning on it taking its place
? O2 is the only option for pH increase as far as safe gasses are concerned. I will agree that Ca(OH)2 is a fine choice for using the CO2 in the water CO2 + OH -> HCO3, but with elevated levels of CO2 indoors the pH will fall back to its low levels with in a few hours.
O2 (out door air) Is the easiest way to fix the problem of elevated CO2.
Oxygen is for sure a very dangerous gas as far as fires are concerned but it is of no danger to people or objects as a gas. Treatment with Oxygen Gas in medical facilities can be of extremely high purity ~90% or higher.
Please don't take this as an attack
I have tried to put in smilies as I do not mean to sound rude.
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jeffmerrill
New member
Here is a great article tha might be useful: http://www.reefkeeping.com/issues/2004-09/rhf/
blanden.adam
Team RC
I didn't see where tom posted this, but if you plan to remove CO2 what are you planning on it taking its place
I will agree that Ca(OH)2 is a fine choice for using the CO2 in the water CO2 + OH -> HCO3, but with elevated levels of CO2 indoors the pH will fall back to its low levels with in a few hours.
O2 (out door air) Is the easiest way to fix the problem of elevated CO2.
Oxygen is for sure a very dangerous gas as far as fires are concerned but it is of no danger to people or objects as a gas. Treatment with Oxygen Gas in medical facilities can be of extremely high purity ~90% or higher.
Please don't take this as an attack
This really isnt true. There isn't a fixed amount of dissolved gas in a reef tank. You can absolutely remove CO2 without adding something to take it's place. Oxygen doesn't really participate in the pH equilibrium either. You could pump pure oxygen into the tank and it wouldn't affect pH, at least not directly.
The reason pumping in air from the outside helps pH is that CO2 builds up in room air, so when your skimmer bubbles the air in you don't extract as much CO2. Outside air often has lower CO2, so you extract more. Nothing really to do with oxygen my friend
.The posted article explains it quite well.
Hello Adam,
This is a nine year old thread;time flies.
Some comments follow in an effort to clarify things for those intersted in more detail.
I agree there is no fixed amount of dissolved gas in a reef tank or in various locations in seawater in the oceans either. Also the concentrations in water vary from those in the atmosphere, generally. Dissolved gases in sea water(nitrogen, oxygen,argon,CO2, hydrogen sulfide, methane et alia vary in proportion and overall concentrations calculated based on gas laws ,such as Henry's law. .Variables like: salinity,depth,temperature and atmospheric concentrations affect the amount of total
and individual dissolved gases in the water.
For perspective ,atmospheric levels are; around 78% nitrogen, 21% oxygen, 10% argon and only .04%( 400ppm) CO2. The water equilibrates to a large extent with the surrounding air at the surface .
In a home or fish tank room the CO2 can easily be 800ppm or even more than twice the amount in the atmoshpere.
As more CO2 hydrolizes , coverts to CO3 and 2 H+( CO2+H2O------>CO3 +2H+), it adds more H+ which lowers the pH. So, lessening the amount of CO2 in the air going into the tank continuously, raises the pH. That can be accomplished with outside air for the room , an outside airline to an aeration device like a skimmer and/ or a CO2 scrubbing device. Increasing the water surface area via the skimmer bubbles and/or surface agitation increase the rate of gas exchange between the tank water and the surrounding air.
Using kalk/lime water( calcium hydroxide Ca (OH)2 slowly and continuously will also continuously reduce the CO2 in water tank water as the oxide forms CO3 by binding with CO2.
I also agree that oxygen has nothing to do with pH and won't raise it or effect CO2 levels ,directly; CO2 independently drives it down and CO2's major source is the surrounding air.
This is a nine year old thread;time flies.
Some comments follow in an effort to clarify things for those intersted in more detail.
I agree there is no fixed amount of dissolved gas in a reef tank or in various locations in seawater in the oceans either. Also the concentrations in water vary from those in the atmosphere, generally. Dissolved gases in sea water(nitrogen, oxygen,argon,CO2, hydrogen sulfide, methane et alia vary in proportion and overall concentrations calculated based on gas laws ,such as Henry's law. .Variables like: salinity,depth,temperature and atmospheric concentrations affect the amount of total
and individual dissolved gases in the water.
For perspective ,atmospheric levels are; around 78% nitrogen, 21% oxygen, 10% argon and only .04%( 400ppm) CO2. The water equilibrates to a large extent with the surrounding air at the surface .
In a home or fish tank room the CO2 can easily be 800ppm or even more than twice the amount in the atmoshpere.
As more CO2 hydrolizes , coverts to CO3 and 2 H+( CO2+H2O------>CO3 +2H+), it adds more H+ which lowers the pH. So, lessening the amount of CO2 in the air going into the tank continuously, raises the pH. That can be accomplished with outside air for the room , an outside airline to an aeration device like a skimmer and/ or a CO2 scrubbing device. Increasing the water surface area via the skimmer bubbles and/or surface agitation increase the rate of gas exchange between the tank water and the surrounding air.
Using kalk/lime water( calcium hydroxide Ca (OH)2 slowly and continuously will also continuously reduce the CO2 in water tank water as the oxide forms CO3 by binding with CO2.
I also agree that oxygen has nothing to do with pH and won't raise it or effect CO2 levels ,directly; CO2 independently drives it down and CO2's major source is the surrounding air.
Last edited:
blanden.adam
Team RC
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