Help setting up a CO2 system

[hulkamaniac]

I've decided as soon as I get back from vacation in two weeks I'm going to start saving up money to redo my 75 g tank. I want to add a "lawn" of dwarf hairgrass and a lot more plants.

So far on my list is :

80 lbs of eco-complete.
a regulator set like this one http://www.bigalsonline.com/BigAlsUS/ctl3684/cp18478/si1431674/cl0/redseaco2prosystemstandard

I know I need a CO2 tank from a welding company or some place as well, but I don't know how big a tank I need. I don't want anything unsightly so preferably it'd be something I can easily hide in my stand. I've also been told that I need a reactor like this http://www.bigalsonline.com/BigAlsUS/ctl3684/cp18478/si1431660/cl0/redseaco2reactor500wpump for my tank, but I'm not sure. Any help would be appreciated.

 

[neilanh]

I'd recommend the following

Milwaukee MA957 regulator/selonoid/bubble counter. You can get them on ebay for $78
For CO2 tank, your local welding shop is a good place. the only difference in tank size is how often you have to refill it. If you don't mind refilling it 2-3 times a year, a 5 lb tank will work great. Or, you can get a 10, 15 or 20 lb tank and refill it less often.

As for a reactor or diffuser, there's many different ways to do this. If you're running a canister filter, I'd highly recommend a DIY inline reactor (Check the DIY forum for details. You can follow someones thread there and build your own, or probably work a deal with them to have one built for you. Checkout Sparky697's thread).

 

[hulkamaniac]

Ok, so I'll need the tank, the regulator that plugs into the tank. The regulator thing I posted from Big Als says it comes with a bubble counter. I'm confused about what all the parts are and what they do. I assume I run a line from the tank to the bubble counter and then to some sort of reactor? Or possibly directly into my canister filter? I'm a little foggy on what all is involved and what all the parts are and what they do.

 

[neilanh]

Alright. So either way you go, you'll get a regulator and a bubble counter. Some units come with a selonoid, which I highly recommend as well.

The regulator does just that, regulates the pressure in the tank (which is around 900psi) to a regulated pressure that you can control. I run mine at about 20-25psi. From there, the selenoid will be hooked up. The selonoid allows you to set your CO2 injection on a timer, and have it click off when your lights are off. Since plants don't use CO2 at night, there's no need to run it, it just wastes gas. Out of that you will have your bubble counter and a needle valve. The bubble counter just allows you a visual way to determine how much CO2 is going into your tank. YOu'll hear people talk about BPS, which is bubbles per second. It's just, like I said, a visual way to determine how much CO2 is flowing. The needle valve allows you a finer amount of control to set the exact flow rate you want. Out of the bubble counter is where you will hook up your CO2 tubing to inject it into your tank. This tube you will hook up to whatever diffusion method you choose. Since you have a canister filter, again I'd recommend a DIY CO2 reactor, like the ones you can find guides on in the DIY section. If you use this, you will hook your CO2 line up to that. Or, if you use a different diffusion method, like the one you mentioned in your first post, you will hook it up to that.

HTH

 

[hulkamaniac]

That is an extremely helpful post. I only wonder if you can tell me how big a 5 lb tank is versus a 10 or 15 and about how much it costs to refill (if you know). Also are there formulas/tables to determine how much to inject into your tank other than measuring PH and KH and caculating from there?

 

[neilanh]

by big, do you mean how tall? You can find the dimensions for the different size tanks online.

A refill on my 5lb tank is about $16.

 

[hulkamaniac]

by big, do you mean how tall? You can find the dimensions for the different size tanks online.

A refill on my 5lb tank is about $16.

Thanks. I think that helps me out. It should enable me to price tanks at the very least.

Also, you said you had to fill your 5lb up 2-3 times a year. I assume I would need a 10 or 20lb tank if I wanted something that I only need to fill up once or twice a year (more low maintenance that way). Is there any way to know if the tank is empty or not other than to notice there are no bubbles coming out of the bubble meter?

 

[neilanh]

I'm just guessing on the amount you'll need to refill on a 75g tank, I don't know. I anticipate refilling my 5lb 1 time this year, but I'm only running a 20g tank on it. YOu'll need more to run your 75, so it was just a guess.

On the regulator, you can monitor the pressure in the tank. Once it starts getting low, you know you're about to run out of gas.