recemdations for CO2 tank size

tinkerman

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Dec 8, 2007
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Trying to figure out how big of a co2 bottle to get for a 120 gal tank with 40 breeder sump. What size tank do most run with a tank this size and how long does it last you? Would like to not have to refill tank more than once a month as it is hard for me to get to the place to get it refilled at in town.
 

Pikez

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I have a 180 gal tank and I go thru 20 lb every month…but I have high light and pH controller. High light really drives fast CO2 usage. If your light is low-ish, you may be able to push 20 lbs to every 60 days or so. So to answer your question: 20 lb tank.
 

Disco Frank

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gsjmia said:
The bigger the better-but a 20lb tank is about as big as you can comfortably carry and put in the car.

so to me thats 9kg....


question is this 9kgs of CO2? or is that the weight of a filled tank?


9kgs of c02 in a month is FOOKING huge


I have a 2.6kg CO2 tank which holds 2.6kg of CO2 = 5.7lbs of C02


the actual weight of the tank when filled would be close to 9kg/20lbs


my tank is a bit bigger than yours and i will go through my 2.6kg/5.7lbs tank in about 8-10weeks


but it would only be med light no ph controller
 

Pikez

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Disco Frank said:
so to me thats 9kg....


question is this 9kgs of CO2? or is that the weight of a filled tank?


9kgs of c02 in a month is FOOKING huge


I have a 2.6kg CO2 tank which holds 2.6kg of CO2 = 5.7lbs of C02


the actual weight of the tank when filled would be close to 9kg/20lbs


my tank is a bit bigger than yours and i will go through my 2.6kg/5.7lbs tank in about 8-10weeks


but it would only be med light no ph controller

Yes, 9 kg or 20 lb of CO2 in about a month. I know that is a LOT. Big tank + surface agitation + high biomass + high light + high CO2 levels will do that. CO2 is cheap but the inconvenience of getting the tank replaced is more of a pain. That is why a 20 lb CO2 tank makes most sense, even for smaller tanks, if you have the room.


FWIW, the same set up with low light + medium CO2 makes the 20 lb tank last twice as long.
 

tinkerman

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Thanks for the responses. Will have to check my stand dimensions to see if it is tall enough or if I may need to go with 2 10# tanks. Pikez can I ask what you are running for lights to know what you consider high light or if you know what par you have at sand bed?
 

Pikez

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tinkerman said:
Thanks for the responses. Will have to check my stand dimensions to see if it is tall enough or if I may need to go with 2 10# tanks. Pikez can I ask what you are running for lights to know what you consider high light or if you know what par you have at sand bed?

Was running three 72" BML Dutch xB on the rim. Way too bright. It was a tightrope walk with high CO2. Very hard to find balance. Now operating with just two lights. Should have bought the damn dimmer first. CO2 use has dropped off significantly with just 2 lights. Plants doing much better too.
 

Matt F.

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I would go with the largest size you can fit in your place. Aquariumplants.com sells 50# CO2 tanks for a reasonable price. You can also check your local brew shops. I currently have 3 20#ers. I've been running the same 20#er on my ADA 60P since December 1, 2013. Still has plenty of gas. The larger the tank, the less often you have to get them filled. ;)
 

PhilipS

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Put the tank in a closet and run rigid CO2 line across the room tucked under the baseboards, or through the walls with your ethernet data cables.


For the 50# tanks, visit your local Air Gas, welding supply, hydroponic shop, brew your own or even medical supply for a tank.


May be cheaper to do the exchange program than buy the tank in some areas.
 

shoggoth43

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The exchange program is usually not the cheapest option, but you at least don't have to worry about buying a new tank or having it tested. OTOH, the tanks you get usually look like crap.
 

Aquarist

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shoggoth43 said:
The exchange program is usually not the cheapest option, but you at least don't have to worry about buying a new tank or having it tested. OTOH, the tanks you get usually look like crap.

It varies for your location I suppose. Where I live, Raleigh NC, there is only two places that refills co2, one only fills tanks twice a month and the other is about an hour each, but both of the places charge about $30-$35 to fill my tanks. So I have been going to a local hydroponic/home brewing store and they exchange 20 pound canisters for $20, that is the best deal I have found, and they are relatively close.


I do agree tho you do get some ugly tanks from the exchange system. It doesn't bother me right now, but what I plan to do when I get some free time is to fashion a co2 canister "Sock" so I can just slip the canister into a cloth cover and won't have to see the uglyness! The 20 pounder won't fit under my 75gallon aquarium, and since I'm running a sump in the 180 there isn't much room for one inside the stand on that aquarium either, so I figure the "sock" would be a quick and easy fix, and if your handy with sewing machine and you can make a bunch of different socks with different colors and patterns.
 

shoggoth43

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I may have to check the local brewing/hydro places as well. The Welding place tends to vary a bit in how much they charge.


The sock idea is an excellent work around to the appearance problem.
 
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