Reddit reviews MOD Complete MDC99005 CO2 Regulator Aquarium Mini Silver Stainless Steel Dual Gauge Display Bubble Counter and Check Valve w/Solenoid 110V Fits Standard US Tanks - LP150 PSI - HP2000 PSI Accurate

• Regulator-$60
  
  
• 24 oz paintball tank-$23
  
  
• Paintball to CGA-320 adapter-$10
  
  
• Airline tubing-$7
  
  
• Diffuser-$12
  
  Total for everything is $112 not including tax.
  
  I use this regulator and the needle valve is a bit touchy, but its solid and works well enough. The solenoid has never stuck either. You can set it and forget it.
  
  People are going to call out using airline tube vs CO2 proof tubing. CO2 proof tubing is completely unnecessary at the pressures what we work at and isn't very flexible, so I like the airline better.
  
  This is my favorite diffuser because it has a halfway decent check valve, it has a build in bubble counter, and you can remove the ceramic disc without taking everything apart. I have 4 of these running in different tanks and 2 have had zero issues. The other two had small leaks that I sealed with gorilla glue and they've worked perfect since.

After a couple weeks of researching the same thing, I wound up assembling my own rather than getting a kit. I have a 60g with a 5lb tank that I got from a local welding supply store that fits nice in my compact cabinet. Tank cost $60 and $15 to fill/refill. Attached to that is this regulator which I run on a wemo plug to come on only when the lights are on. I use this diffuser (which I think is overkill). All connected by this CO2 proof tubing. Finally, I use this drop checker. Less than $200 invested. It's silent except for the instant that the solenoid switches off/on. I have to trim plants a couple times a month. At two bubbles/sec, I get about 6-8 months between tank refills. Slightly cheaper option may include a paintball tank with adapter.

I got this regulator which has worked very well for me. It has both high and low pressure gauges, built in bubble counter, and check valve with solenoid. Last last part is key because you can put it on a timer. CO2 at night is basically useless and can potentially raise levels too high (and it decreases the frequency of needing a refill.)

Yes, my regulator includes the electronic solenoid that opens 15 minutes before my lights turn on and closes 15 minutes before my lights turn off.

My atomizer sits just below my Hydor 240 powerhead which turns on and off with the Co2.

So I’m using:

A 5Lb bottle of Co2 from my local Airgas company

This regulator with a built in solenoid and bubble counter: https://www.amazon.com/gp/product/B07C6HKTN6/ref=oh_aui_detailpage_o00_s00

This atomizer: http://greenleafaquariums.com/co2-diffusers/atomic-diffuser-50.html

A permaseal so I don’t have to fool with those plastic washers that go in between the neck of the Co2 tank and the regulator. My regulator had one, but you can get them cheaply online if yours doesn’t.

Co2-proof tubing

A check valve in between the diffuser and the regulator

A drop checker inside of the tank

Black suction cups to position the tubing against the glass since the Co2-proof tubing is more rigid than regular airline tubing.


I originally bought a paintball setup (paintball tank and an adapter for the regulator so it will fit together), but then found out no one in town had systems that weren’t broken to refill the tank (Academy, Dicks Sporting Goods) so I sent them back and got the 5 pound tank from Airgas. I’m glad I did. It’s been running 8 hours a day since June and is still reading 800-1000 PSI on the tank pressure side.

Basically, you need a tank, a regulator some airline, a bubble checker would be good to have and a diffuser. Also, you'd like a timer of some sort as you really do not need to have co2 running 24/7 nor would you probably want to.

My setup:

• 24oz Paintball co2 tank: $30 at paintball shop filled with co2.
  $23 dollars on Amazon - though I would have still needed to get it filled at paintball shop for $5 which brings it $28. $2 more - i think it's better at that to support the local shop and plus I didn't want to wait for the tank to come to my house as that would have arrived later than anything else.
  
  
• Adapater to utilize paintball co2 tank - $9 on Amazon
  
  
• Bubble Counter - $10 on Amazon I know the regulator has a bubble counter, however with the paintball tank it would not work as it'll be horizontal instead of vertical - you can choose cheaper ones. I just liked this $10 one. Btw a bubble counter will show you how much co2 you're adding or at least how fast as not every bubble counter counts it at the same pace but a good gauge to see how much you are adding - ie. you really cannot ask how many bubbles per second you should be running. the 1-2 bps that I run might be different on your bubble counter)
  
  
• CO2 Regulator - $60 on Amazon
  
  Price for this setup: $109
  
  If you need a timer, there's plenty of options. I already had one, but you can find them on Amazon.
  
  
• I was able to get this one as an add-on for $3.54 for something else though now it's $14.50 :/ and ironically I switched to a smart switch idea for my build anyways.
  
  
• Got this smart switch to control my autodoser and some other things -if it works it's a good $20 spent.
  
  Though in the end, you would need a timer and if you already have one then you won't have to buy one. Or if you have extra smart switches either that you can set a schedule on.
  
  Other tanks:
  
  Instead of the paintball tank you can get a regular co2 tank:
  
  
• 5lb from Amazon - $62 + ~$20 to fill at an air place It would have brought my setup to $141 if I went that route. It might be $50 more than the paintball tank, but it only increases price by $40 because you don't need the adapter nor the bubble counter. Pros: It could be cheaper. 24oz paintball is $5 to fill(in most places) a 5lb which is ~80oz can be anywhere from $10-$20. If it's on the lower end of that range where you live it's cheaper. Other pro is that less often you need to fill it. Negative: Larger and harder to hide. It won't fit in my setup or how I have my tank setup.
  
  Of course, that's just buying the stuff to build the system.
  
  You can watch videos about it on Youtube like Aquarium Co-Op's Co2 guide but I can still try to break it down.
  
  Get tank and properly secure it to the regulator.(I'd recommend watching a video on that as the regulator does need to be open for this part apparently). If using the paintball tank, secure the adapter to regulator first. DO NOT secure it on the paintball tank first. If you do it with the way the adapter is built, I'm guessing you'd be losing a bit of co2. Though, I haven't tried it, I'm logically thinking that it ain't good. If you use a 5lb tank or larger, there's something about some disc or gasket or something that is supposed to help keep it from leaking. I'm going to refer you to youtube on that one. I didn't use any on my paintball setup except for the gasket already on the tank. I did use some plumbers tape on the adapter to regulator though. I'm just hoping I don't have a leak and I'd be pretty confident to assume that I don't as I still have CO2 in my tank after a couple of weeks.
  
  All you need to do now is to attach the airline hose(some people will say to use co2-proof hose to prevent co2 loss, but I decided to skip that and you can decide what you wish to do as I might be right or wrong on that part along with other people who claim airline tube is sufficient) to the regulator. So after you attach the hose to the regulator, attach the bubble counter somewhere along the line before the aquarium(I think I did that right). Of course, if you use the 5lb or larger tank, you should be able to use the bubble counter that came with the regulator as it would stand vertical. The line eventually gets connected to a co2 diffuser which will break up the co2 into smaller bubbles to easily be dissolved better into your water. Of course, there are other ways to get the co2 into your tank, but this is the way I do it. Youtube can show you other ways, or other redditors for that matter. One thing to note is that you should also have a check valve to prevent water from going from the aquarium to your system. It should most likely be closer to the water than the co2 system. The bubble counter I use, also has a check valve for whatever that one is worth. Some diffusers come with bubble counters and check valves as well. Speaking of diffusers, i forgot to add that to my price. but that can run anywhere from $5 on up. Also the diffuser might have to be cleaned due to algae once and awhile.
  
  The system should be ran using a timer to coincide with your light cycle and should run basically when the lights are on. I turn my co2 on 1 hour before the lights turn on and turn it off 2 hours before the light turn off. Hypothetically, you can run it 24/7 however it's better not to as the risks are a bit too much for putting something in your tank that is not being used as the plants typically don't use co2 with the lights out and you can risk running into a situation where you deplete the oxygen in your fish.
  
  Overall, I think it's worth it at least for me. But also be cautious that adding too much co2 might be detrimental to your fish. If you are running it and your fish are all gasping for air, you definitely are putting too much in but you should never get it that far which some way to check it would be a good purchase for this. I just use the method of figuring out the ppm of CO2 based on pH and KH. I'm not sure how accurate it might be but it has been stable and my fish are doing fine as well as my plants and the algae is at bay. There's also what's called a CO2 drop checker that you can purchase to measure this.
  
  If you really want to get into this, I'd recommend researching it further yourself and maybe wait on some other more "experienced" redditors to answer as I might and could be wrong on some things. I know I've read some people don't think the ph/kh calculation method is good and to buy a drop checker, but I'm pretty confident in using it for my tank but I might be undosing the co2 for all I know. Though on the flipside, I could be overdosing, though my fish are not showing any signs of symptoms of said overdosing. But I could be wrong on that. If I am, please let me know. :) Definitely do your own research, like you should on anything. :) At least, get a good footing and confirmation from other sources.

This is crazy, cause I had this list put together, let me know what you think of this stuff? May go with your diffuser tho as it seems cheaper, is it also a c
Drop checker or do I need to get one of those too? Also, should I be dosing stuff on top of this CO2 setup? Like should I use Excel and other stuff still?

Ohhh ok, wasn't sure if you tried cutting the top off of it or not.

JT CO2 Tank 12oz w/repeater https://www.amazon.com/dp/B0008G2WAM/ref=cm_sw_r_cp_apa_i_-t03AbGZWQRJ7


Interstate Pneumatics WRCO2-5A4 CO2 Paintball Tank CGA 320 Adapter https://www.amazon.com/dp/B00I2UMZ2Q/ref=cm_sw_r_cp_apa_i_iu03AbTZCMEKR

CO2 Regulator Aquarium Mini Stainless Steel Dual Gauge Display Bubble Counter and Check Valve w/ Solenoid 110V Fits Standard US Tanks - LP150 PSI - HP2000 PSI Accurate & Easy to Adjust Comes w/ Tools https://www.amazon.com/dp/B07C6HKTN6/ref=cm_sw_r_cp_apa_i_Fu03AbFC8ZJ3S

Rhinox Glass Drop Checker Kit - 3 Seconds to Read CO2 levels - 3 Minutes to Setup - Fastest way to ensure sufficient Co2 in Planted Aquarium - Includes pH Reagent indicator solution & Color chart https://www.amazon.com/dp/B005C74ZCA/ref=cm_sw_r_cp_apa_i_Xu03AbX7A0N5G

Pollen Glass CO2 Diffuser with U-Shape Connecting Tube for Aquarium Planted Tank (20 - 50 US gallons) https://www.amazon.com/dp/B01N2LZOCE/ref=cm_sw_r_cp_apa_i_dv03Ab406ZNJT

AQUANEAT 25 FT Airline Tubing Suction Cups Control Valves Tee's Check valves Aquarium Air Pump Accessories https://www.amazon.com/dp/B076Z8ZR9H/ref=cm_sw_r_cp_apa_i_sv03Ab2DJ19BC

Rhinox Brass Check Valve for Aquariums - Sturdy, Reliable, Anti-Leak, Anti-Backflow, Non-Return CO2 Air Valve That Ensures One Directional Water Flow, Perfect for Sensitive Fish https://www.amazon.com/dp/B00IHXW5SC/ref=cm_sw_r_cp_apa_i_Gv03Ab2QEHCZQ

I am using this regulator and this adapter with some cheap co2 paintball tanks. Been working great so far, the solenoid valve is really useful.

Minimum Setup is only 3 items

Tank

regulator

Diffuser

This one? https://www.amazon.com/dp/B07C6HKTN6/ref=cm_sw_r_cp_apa_sfLJBb1FJRD9S