Rex's Planted Tank Guide

Your Source Of Information For Planted Tank Aquariums, Lighting, CO2 & Fertilizers

Getting Started With CO2

Getting Started: Alright it seems that setting up a CO2 system is a complete and total mystery to many people. I'm a mechanical dunce and yet I manage to build and setup my own systems. Perhaps I'm an idiot savant. So I'm writing this page to show you the very basic steps to hooking up a pressurized CO2 system. Note that the product shown in the pictures is the product I build and sell. But the basics remain pretty much the same.

Setting Up A Pressurized System

Step One


These pieces should be pretty easy to find for most people at a decent hardware store.
1. Regulator Nut

See that! That's a regulator sitting on a cylinder. Note the crappy green blob with the #1 in it (Hey! I'm not a artist). That's the regulator nut. You need to tighten up that nut with a wrench. Get manly on it. You can't break it. Also note that not shown is the fact that you need a washer in that connection. A NEW washer every time you remove the regulator. Or you can use a Permaseal (like I have installed on that cylinder). There is no need to put Teflon tape on the cylinder threads. They add nothing to the sealing ability of this connection.

Step Two


These pieces should be pretty easy to find for most people at a decent hardware store.
2. Cylinder Knob

See that big knob on the top of the cylinder? That's the cylinder knob. And once you have the regulator attached (Stop right now. Get your wrench and give that regulator nut another good turn) you need to fully open this knob. If you hear noise then go back to the previous step. Some cheap regulators have very precise directions on how to open up the cylinder knob. It's about a 10 step process to avoid damaging the regulator. When I gave a copy of those directions to the shop where I buy my regulators it took them 30 minutes to quit laughing.

Step Three


These pieces should be pretty easy to find for most people at a decent hardware store.
3. Working Pressure Lock Nut

Ok, if I have not already lost you in the details or bored you to death the next step is to adjust the working pressure. With my units you use this screw here. Screw it IN to raise the working pressure. Note that bad arrow? It's pointing to the lock nut. You can tighten that down once you set the working pressure so that it can't be "accidentally" changed my rug rats playing with the system. I suggest setting the low side pressure to between 10-15 psi. Note that some regulators are not adjustable.

Step Four


These pieces should be pretty easy to find for most people at a decent hardware store.
4. 11 p.s.i.

See... 11 p.s.i. Not bad for a grumpy old guy. I believe that having a regulator that you can adjust is, at the very least, a convenience that other manufactures don't offer.

Step Five


These pieces should be pretty easy to find for most people at a decent hardware store.
5. High Side Gauge

Picture of the high side gauge. Note that this will vary depending on the ambient temperature.

Step Six


These pieces should be pretty easy to find for most people at a decent hardware store.
6. Needle Valve & Bubble Counter

Ok, that's a really poor picture of the needle valve and a very ugly home made bubble counter sitting there for testing purposes. By now you should have plugged in the solenoid if you have one (if I have to show you how to plug something in then please get your mommy to help you with these directions). You now adjust the needle valve to the desired flow rate (bubble count). Note that will vary with every tank and CO2 system. You want to get enough flow rate to reach the desired CO2 levels in the tank. Those levels are considered right now to be 30 ppm or a full point drop in the pH.


If you look carefully at the picture you will notice there is a lock ring under the adjustment knob. You can tighten this down to prevent "accidental changes" in the flow rate. Once again. If you have any questions or comments then contact me.