# Has anyone ever heard of using one CO2 tank on two aquariums?



## piffy (Oct 2, 2010)

Hi all,

I currently have a 5lb CO2 tank that is working beautifully with my 20 gallon long. I'm currently setting up a new 8 gallon tank and was wondering if I could use the same CO2 tank on this one as well.

I have one of those Y-split connectors as well as a plastic valve that can control individual bubble rate and a separate check valve. 

Is this silly? I'm kind of broke right now after buying everything else for my new tank, so I can't shell out the extra money for a new pressurized CO2 system. I really don't want to go DIY as my previous experience with it was unstable and messy.


----------



## Higher Thinking (Mar 16, 2011)

You can definitely do it, but the best way is by using a splitter on your regulator and then using multiple needle valves. Obviously this is more expensive, but certainly the most reliable. I wouldn't trust those dinky plastic flow controllers to not gas the smaller tank. It is definitely possible but using the same needle valve will make things tricky.


----------



## OverStocked (May 26, 2007)

Yes it can be done, but I wouldn't put that little airflow controller anywhere near a pressurized system. You'll just end up frustrated and out more money. 

There are several co2 setup retailers here that can help you out.


----------



## Postal Penguin (Mar 30, 2009)

Those air valves leak air so a good amount of CO2 will vent right into the air. 

Like others have mentioned you should split the CO2 after the regulator/solenoid and use separate needle valves. You can pick up the necessary materials to split the CO2 at any local hardware store for <$25. Just need some brass fittings and some gas rated plumbers tape.


----------



## Capsaicin_MFK (Nov 15, 2009)

This is pretty much the only safe way to do it.


----------



## xmas_one (Feb 5, 2010)

Sweet setup! ^^^


----------



## kevmo911 (Sep 24, 2010)

...And if you were to use a solenoid valve (advisable), it would go between the regulator and splitter. As has been suggested, you're best off using two identical needle valves after the splitter. You're also not limited to two tanks. Many folks have multiple tanks on a single cylinder/regulator/solenoid. I have one regulator running three tanks. One cylinder, one regulator, one solenoid, three needle valves, three bubble counters. The needle valves and diffusers are identical, and the tanks are three different sizes.

You can use a tee splitter for two tanks or a cross splitter for three tanks. Or any combination of splitters for many many tanks. I have two tee splitters for three tanks.


----------



## Bettatail (Feb 12, 2009)

nice concoa 312, and all fittings are swagelok.
if you don't use it with solenoid, you can actually get a shutoff valve and put between the regulator and needle valves.
I will show you a setup later, with the shutoff valve, non solenoid setup. 



Capsaicin_MFK said:


> This is pretty much the only safe way to do it.


----------



## KH2PO4 (Jul 18, 2009)

Most plastic valves (for using with air tubes) leak to some degree. 
Try this http://www.youtube.com/watch?v=5RxQgj09bMc :red_mouth


----------



## Justintoxicated (Oct 18, 2006)

you can get a manifold and inline needle valves which will be the most accurate, but I do think I would like having the valves attached to the regulator too rather than hanging off the line.


----------



## btimmer92 (Mar 12, 2011)

OverStocked said:


> Yes it can be done, but I wouldn't put that little airflow controller anywhere near a pressurized system. You'll just end up frustrated and out more money.


Ha, +1 to that


----------



## VaehZaza11 (Aug 28, 2014)

bettatail said:


> nice concoa 312, and all fittings are swagelok.
> If you don't use it with solenoid, you can actually get a shutoff valve and put between the regulator and needle valves.
> I will show you a setup later, with the shutoff valve, non solenoid setup.


please explain everything i need for this set up!!

Bump:


Capsaicin_MFK said:


> This is pretty much the only safe way to do it.


i NEED TO KNOW HOW EXACTLY TO RUN THIS SET UP PLEASE


----------



## Timmy!! (Jun 26, 2014)

Im going to have to copy that setup! Thanks for the idea


----------



## flight50 (Apr 17, 2012)

Capsaicin_MFK said:


> This is pretty much the only safe way to do it.


That's not the only safe way. I am doing a setup that is very similar to this GLA Pro-5-ss http://greenleafaquariums.com/products/gla-pro-5-ss-co2-regulator-two-stage.html. I will post my setup in due time but I still need to purchase my needle valves and my 20lb co2 tank. My setup will end up serving 8-9 tanks. Air valves and splitters are not recommend for pressurized co2. Gas travels the path of least resistance so one or more tanks can get starved out. That won't be a good thing.

Also reference this link http://www.plantedtank.net/forums/showthread.php?t=148509 to get familiar with the parts. In this link, follow the three links within that first post by olpunk78 for some additional learning. From here, there are several possible outcomes to make a successful CO2 setup.


----------



## charlie 1 (Oct 22, 2006)

A quick search on TPT resulted in these threads, here are a few among others. They should give you a better understanding of how to do it
http://www.plantedtank.net/forums/showthread.php?t=614442&highlight=splitting+co2
http://www.plantedtank.net/forums/showthread.php?t=591113&highlight=splitting+co2
http://www.plantedtank.net/forums/showthread.php?t=397498&highlight=splitting+co2
http://www.plantedtank.net/forums/showthread.php?t=466753&highlight=splitting+co2
http://www.plantedtank.net/forums/showthread.php?t=307505&highlight=splitting+co2


----------



## talontsiawd (Oct 19, 2008)

flight50 said:


> That's not the only safe way. I am doing a setup that is very similar to this GLA Pro-5-ss http://greenleafaquariums.com/products/gla-pro-5-ss-co2-regulator-two-stage.html. I will post my setup in due time but I still need to purchase my needle valves and my 20lb co2 tank. My setup will end up serving 8-9 tanks. Air valves and splitters are not recommend for pressurized co2. Gas travels the path of least resistance so one or more tanks can get starved out. That won't be a good thing.


GLA's setup is the exact same thing, the only safe way to do it is using a second needle valve, plain and simple. Bubble counter is optional. You even add extra solenoids if you want things going on and off at different times if you wanted but that is likely overkill unless tanks are on very different schedules.



Anyway, as for the OP, it is not uncommon at all to run CO2 to multiple aquariums off the same CO2 tank. The only reason some don't is they don't know they can, or the tanks are too far away to make it reasonable to do so. In many ways it makes more sense to do it this way, unless you have extremely large tanks because it's simpler and has less points of failure. The reason you need two needle valves is a few. First, most people will have different sized tanks with different CO2 needs. However, even if they are the same size, if one diffuser clogs, without a needle valve, the one tank will get less CO2, the other more, which could be very problematic to disastrous. The only application I could see just a splitter being an option is using two identical tanks with reactors but even then, I would use a needle valve for each reactor for insurance. It not hard to do this, you can buy a manifold online or simply buy brass T's at your local hardware store. They even make inline needle valves or you can adapt some to go inline if you don't want to change it on the regulator, here is an example of an inline, though most needle valves can be used inline by adding a brass nipple to them- http://www.adana-usa.com/index.php?main_page=product_info&cPath=76_1_4&products_id=62


----------



## flight50 (Apr 17, 2012)

talontsiawd said:


> GLA's setup is the exact same thing, the only safe way to do it is using a second needle valve, plain and simple. Bubble counter is optional. You even add extra solenoids if you want things going on and off at different times if you wanted but that is likely overkill unless tanks are on very different schedules.


The pictures I referenced gave just that...2 pictures with no explanations. I wasn't referring to using a second or multiple needle valves. I am referencing the fact that GLA is using a solenoid attached to a manifold. Multiple needle valves are on that manifold and bubble counters after that. The picture I quoted, uses a tee to one needle valve and an elbow to the other needle valve. There is a lack of a manifold and also a lack of a solenoid. I don't see how this is the exact same as GLA's setup. Concept yes, the build no. Therefore the picture I quoted is not the only way the setup can be done. It could also be pulled off with pvc pipe and that would be different as well. One could also strand several tees together and then an elbow on the end to make a pipe fittings manifold.


----------



## talontsiawd (Oct 19, 2008)

flight50 said:


> The pictures I referenced gave just that...2 pictures with no explanations. I wasn't referring to using a second or multiple needle valves. I am referencing the fact that GLA is using a solenoid attached to a manifold. Multiple needle valves are on that manifold and bubble counters after that. The picture I quoted, uses a tee to one needle valve and an elbow to the other needle valve. There is a lack of a manifold and also a lack of a solenoid. I don't see how this is the exact same as GLA's setup. Concept yes, the build no. Therefore the picture I quoted is not the only way the setup can be done. It could also be pulled off with pvc pipe and that would be different as well. One could also strand several tees together and then an elbow on the end to make a pipe fittings manifold.


I understand. I wasn't trying to make an issue but the point is, two needle valves are the way to go. Using several Tee's is really the same as a manifold, I think a solenoid is a great idea but not at all necessary. It's not exactly the same, it follows the same concept, each tank needs a needle valve. If you use a bubble counter, you need one per tank. If you use a solenoid, you probably only need one, most would only use one, but you could use more than one if you wanted to. 

I understand the differences but I just wanted to explain the concept. That is why I said it doesn't even have to be on the regulator, you could use a complete regulator setup and just split the line and add two inline needle valves too, just leave the needle valve on the reg wide open. Or adapt that to be inline and have no needle valve on the post body, have it all inline. You will still have the same setup, more or less, same functionality.


----------

