(I will update the following post as parts come in)
Ok, I've been meaning to put this together for quite some time, and finally want to get going on it. There are hundreds of CO2 build threads on sites like this and I don't mean to replicate or copy any of them. It won't be a parts list either (the possible parts that will work are endless), but more of a basic build with cost as the driving force. I will say this though... building this isn't for everybody. There are plenty of people willing to build these for you if you post in the WTB section of the forum. If you don't feel confident in ANY aspect of building your own setup,
don't do it. You shouldn't be gambling with something with close to 1000psi just assuming/hoping you're correct.
In order to make this work with my goal in mind, you'd have to fit the following criteria:
- NOT be in a rush/hurry
- Enjoy shopping around on eBay
- Enjoy digging through spec sheets and pdf's on company websites
- Enjoy reading previous build threads dating back years
My goal here was to put together a complete (minus tank/CO2 filling) dual stage CO2 setup for $100 or less. By complete I mean, regulator, selonoid, and needle valve. I didn't care about looks, brass vs stainless steel, new vs used, or any aspect regarding looks. This is all about low cost and function with reliable parts.
Like I mentioned, if you are in a rush, this isn't for you. Many of the key components take weeks of watching eBay and searching to find at a reasonable cost. I also save a fortune by purchasing fittings overseas. I can't meet my $100 goal buying a $12 nipple locally, but I can meet it buying that same nipple for $1.58 shipped to me from an online source.
I'll need the following:
----------------------------------------------------------
Regulator- I want a dual stage regulator to avoid the possible "end of tank dump" scenario. If you're going to eBay for this like I did, keep the following in mind... Many sellers have no clue what they're selling, have no idea if it works, and won't accurately respond to a majority of your questions. Do your own homework and look up the difference between single/dual stage regulators. You can identify 99% of them by looking at them. Yes, using eBay is a gamble, but often pays off. If you're unwilling to gamble, look for a buyer that accepts returns (often drives up the price though) or continue searching for only "new" items.
Here's my choice... I found a Fisherbrand Mulit-Stage (dual stage) reg on eBay shipped to me for $31 after sending a "best offer". It's a good start for this budget build. Fortunately it has the CGA-320 connection already on it. That is the connection needed to connect to our CO2 bottles. More than likely you will find one with a different CGA fitting installed... no worries, it will cost you $10 (eBay) to swap it out. A quick look at the specs show that it's a CGA-320 inlet, 3000psi inlet pressure, 1-40psi outlet pressure, multistage brass regulator (originally priced at $700+). The one thing you'll notice looking for a reg is that many look identical. There are many companies (like the one I used) that slap their name on a reg manufactured by Harris, Victor, or Concoa (Concoa 432 series are my favorite).
![]()
![]()
![]()
The reg I chose wasn't some sort of a fluke. Each of the regs in this pic were purchased for under $55 (including the new ones still in the boxes). You just need to be patient looking and dig deeper than most when you search.
----------------------------------------------------------
Fittings- Here's where I'll pull ahead a little $$-wise. I'll make a few assumptions/generalizations as I create a parts list. I will need a fitting to connect my regulator output to my solenoid, another to connect my solenoid to my needle/metering valve, and another to connect my needle valve to my tubing going to my aquarium.
Most regulators (here in the US) will have an output thread that is 1/4" FNPT (Female- National Pipe Thread). Most solenoids have a manifold in/out thread that is 1/8" FNPT. Fitting 1 will be a 1/4" x 1/8" nipple. Quick check on eBay... $1.19 shipped to my door (stainless steel).
Next connection is the solenoid to the needle valve. This one is simply a 1/8" nipple. Back to eBay and another $1.25 shipped to my door (also stainless).
Final connection is from the needle valve to my tubing. The cheapest way I can go here is either a 1/4" tubing x 1/8" MNPT push to connect, or in my case a 1/8" NPT x 3/16 barb check valve from ARK-PLAS. (I believe it was
@PlantedRich from this forum that mentioned ARK-PLAS and turned me on to them-thx!). Price? Not sure how to list this one... ARK-PLAS shipped me out a few to try for free upon inquery. I'll go with $0.00 here, but if I went with the push-connect it would be 2.39.
Total fittings cost: $2.44
Here's the parts:
--- current total: $33.44, updates to come ---
