# PSI for 10 lb CO2 tank



## Jlanders001 (Mar 31, 2009)

What total PSI are you guys getting right after a refill? I want to make sure I'm getting what I'm paying for.

My 10 lb tank after a refill is about 900 PSI. Does that sound about right? What is the generally the max PSI these tanks can hold?

JTL


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## nokturnalkid (Feb 27, 2007)

Psi really isn't that big of an issue in when you refill. Should be in the 800 to 1000ish range. Just weigh your tank when it is empty. Then weigh your tank when it is full. It should be 10lbs or so heavier when full. The weight of the empty tank should also be stamped onto the tank.


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## Seattle_Aquarist (Mar 7, 2008)

Hi Jlanders001,

The PSI you read on your tank pressure gauge is dependant on your ambient room temperature. The only time the tank pressure will drop substantially is when the tank is nearly empty and all the liquid CO2 has been converted into gas. 

The way to determine if you are getting a proper fill is by weight. A 10# tank will weight 10 pounds more when full than when it is empty.


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## Jlanders001 (Mar 31, 2009)

By weight! Man, I knew that - just was not thinking at the time! It's been a long week.

So the next question is how to determine one's optimal bubble per second ratio. Is there a rule to go by, or do people just go by how the plants respond?

My tank is a 180 gallon. I have it running about 2 bubbles per second right now and pH stays around 7.4 to 7.7. Its only been a few days since I've set this system up. I guess it will take some time, but I have not seen any signs that the plants are benefiting from it yet.

Also, do people run pH controllers 24/7 or put them on timer/day/night cycles with the lights? Seems kinda weird to have CO2 running at night time, ya know?

JTL


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## nokturnalkid (Feb 27, 2007)

There is no bubble rate that will be the same from tank to tank. There are many factors that go into determining bubble rate like diffusion method, surface agitation, etc. Get yourself a dropchecker with a real 4kdh solution. When the solution is green, you are pretty much in the right spot. Then just tweak it from there on in. I've ran co2 24/7 and there is no need for it. I just didn't turn it off because my regulator never had a solenoid for it. Now that I do have a solenoid, I turn the co2 on about an hour before lights go on and off about an hour before lights out. Just monitor how long it takes for your drop checker turns green. That will tell you when to turn on your co2.


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## Jlanders001 (Mar 31, 2009)

Cool. I have one of those CO2 checkers. Mine is the one from Red Sea. It is in the green now so I must be close to, or have arrived at, my optimal rate. 

Does two bubbles per second sound like a typical planted tank?

JTL


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## nokturnalkid (Feb 27, 2007)

2 bps sounds a bit on the low side for a 180. If you have a 4kdh solution for your drop checker, sorry not to familiar with the solution from Red Sea, then you should be good to go. But, like I said earlier, there are many factors that go into determining a proper bubble rate.


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