DIY co2 System

[Mengo]

I am planning to set up a diy co2 system for my 10gal. But I have a few concerns. For example, if I run it at night will i end up gassing my fish? And is there a way to turn it off conveniently? I am planing on using two 1L bottles and the recipe i'll be using for each bottle is 1 cup sugar, 1/2 tsp baking soda, 1/4 tsp baking soda. Is this too much or too little for my tank? Any tips for diy co2 in general? What are the "don't"s when setting it up? Thanks:)

[Koi]

You can use an airline valve to close off the gas at night or just run an airstone when lights are off. In general the diy co2 won't create enough co2 to gas your fish

I think these videos will be helpful for you, he also has a few little tweaks you can do for quality of life if you're handy. I would say just don't buy the solenoid or the pressure gauge.

If you can afford a solenoid or have a little more of a budget, I'd would reccomend going this route. 

I think this is a nice middle of the road and you can save some money buying the bike co2 cartridges. This guy has a few more videos on the subject, I would definitely check em out just to cover your bases.

[Mengo]

 

7 minutes ago, Koi said:

You can use an airline valve to close off the gas at night or just run an airstone when lights are off.

If I close the gas off, won't the bottles explode? And what exactly does an airstone do, I know it's used to split the bubbles but how does that help with not gassing the fish? Will the amount of co2 i'll be injecting lower the ph of my water significantly? 

[Koi]

If you're not overdoing your mix it shouldn't explode. But If you don't want to worry about that then I would say just run ain air stone at night for peace of mind. 

The point of the airstone is that it will create surface agitation to allow gaseous exchange in your water. To put it simply it will gas off the co2.

The co2 will affect your ph but as long as you have some KH, I wouldn't worry too much about it. Definitely keep an eye on your tank and monitor parameters the first couple weeks when you do it. Running an air stone at night will also offset your ph from dropping too low.

In general depending on how well you can even diffuse the co2 into your water, the diy bottle won't make enough to gas your fish or crash your ph. Be sure to have good flow and surface agitation

[Koi]

I forgot to mention get a check valve

[Mengo]

I know. Thanks tho

[Brandy]

2 hours ago, Mengo said:

I am planning to set up a diy co2 system for my 10gal. But I have a few concerns. For example, if I run it at night will i end up gassing my fish? And is there a way to turn it off conveniently? I am planing on using two 1L bottles and the recipe i'll be using for each bottle is 1 cup sugar, 1/2 tsp baking soda, 1/4 tsp baking soda. Is this too much or too little for my tank? Any tips for diy co2 in general? What are the "don't"s when setting it up? Thanks:)

I am very confused by your recipe. It will not make co2. Perhaps there is a typo? Your options would be sugar/yeast (CO2 produced by yeast as it grows, sugar=food for yeast) or baking soda/citric acid (acid-base reaction, more controllable and reliable). I went with the latter recipe. 

My set up has a pressure gauge, and a valve, plus a little magnet to adjust the height of the tubing inside the second bottle. It doesn't matter how much "mix" you put in, you can control how quickly or slowly you produce the gas by adjusting the tubing in the second bottle.

[Mengo]

2 minutes ago, Brandy said:

I am very confused by your recipe. It will not make co2. Perhaps there is a typo? Your options would be sugar/yeast (CO2 produced by yeast as it grows, sugar=food for yeast) or baking soda/citric acid (acid-base reaction, more controllable and reliable). I went with the latter recipe. 

 

I have not tried it so I don't know if it'll work but this is a recipe I found on a few websites. They said yeast and sugar is for the co2 and the baking soda was a ph buffer so the yeast doesn't die so quickly.

[Brandy]

Ah. If you look at your post you say Baking soda, sugar, and Baking soda.

[Mengo]

2 minutes ago, Brandy said:

Ah. If you look at your post you say Baking soda, sugar, and Baking soda.

oops😅

[Brandy]

If you are concerned by explosions and stability, I would opt against the yeast which will change it's metabolisim rate according to the temperature of the environment and the amount of waste product that is in the water. I have tried both and found the baking soda/citric acid to be easier to control. On an up note, explosions are messy, but not scary. No real damage is done, except maybe to your carpet.

[Dancing Matt]

I used the citric acid, had a cheap solenoid that broke quickly. The bottles were soda bottles so they did not explode, they were used to carbonation.

[CT_]

The two bottle approach in nice because its self regulating too.  I'd imagine if you dumped the full dose of baking soda and citric acid you could get a bottle to explode and it would be quite dramatic.  But, I also assume a drilled bottle cap is also much weaker and would fail first, which is probably for the best.

[Mengo]

1 minute ago, CT_ said:

But, I also assume a drilled bottle cap is also much weaker and would fail first, which is probably for the best.

I'll be using a silicone sealant so it won't leak

[CT_]

5 minutes ago, Mengo said:

I'll be using a silicone sealant so it won't leak

I didn't mean leaks.  I meant if there was too much pressure you'd want the lid to break much sooner than the walls of the bottle which can handle quite a bit of pressure.  Failing at a safer pressure is a good thing and probably less clean up too.

[Fish Folk]

Did a DIY CO2 setup for awhile. Used an inverted turbidity column to hold CO2, and slowly dissolve throughout the daylight. Our 29 gal used about 50-ml during daylight. 
 

We gave up, after awhile, because making the yeast mixture got to be a bother. If you’ll find a welding store, and buy a small CO2 tank + regulator, it’s easier than chemistry experiments. Even a CO2 paintball gas canister could work, if a good regulator is added. Ocean Aquarium in San Francisco (the famous “no water changes ever” fish store tour) uses inverted containers. 
 

Here’s an old video we made showing our DIY setup. Yes, the thing will eventually explode one way or another 🤦‍♂️
 

 

[FrozenFins]

Heres a few videos of the King of DIY (aka Joey Mullen) builiding a diy co2 system:

 

They have worked for me. 

[Koi]

1 hour ago, Brandy said:

I am very confused by your recipe. It will not make co2. Perhaps there is a typo? Your options would be sugar/yeast (CO2 produced by yeast as it grows, sugar=food for yeast) or baking soda/citric acid (acid-base reaction, more controllable and reliable). I went with the latter recipe. 

My set up has a pressure gauge, and a valve, plus a little magnet to adjust the height of the tubing inside the second bottle. It doesn't matter how much "mix" you put in, you can control how quickly or slowly you produce the gas by adjusting the tubing in the second bottle.

Sorry I misspoke there, when I did it I ran a rather rinky dink setup with a lot of leftover plumbing supplies which led me to believe there weren't many issues to worry about. If it wasn't apparent I don't really have much of a chemistry/science background haha. I only ran the diy bottles for a few months at a time before I eventually got tired of doing it which might be why I didn't run into any accidents.

[Brandy]

2 minutes ago, Koi said:

Sorry I misspoke there, when I did it I ran a rather rinky dink setup with a lot of leftover plumbing supplies which led me to believe there weren't many issues to worry about. If it wasn't apparent I don't really have much of a chemistry/science background haha. I only ran the diy bottles for a few months at a time before I eventually got tired of doing it which might be why I didn't run into any accidents.

I don't think there are many issues to worry about--this is a low pressure system, not compressed gas. It can be messy, but not dangerous. There are kits that make this easier, for about $20 on amazon (you supply the bottles and chemicals). I recently used one of those and had no issues. Previously, in another life, I had a home made diy one with no valve, and it was fiddly and did "explode" yeast goo out the top occasionally. I lost interest as a result. 

[Fish Folk]

3 minutes ago, Brandy said:

it was fiddly and did "explode" yeast goo out the top occasionally.

Yesssss..... this ^^^ happens 

[Brandy]

1 minute ago, Fish Folk said:

Yesssss..... this ^^^ happens 

I also used to brew 5 gallon batches of beer--that is faaarrr messier when you have a blow out. Your house smells lovely tho! Getting it off the ceiling however...😆

[Mengo]

12 minutes ago, Brandy said:

I had a home made diy one with no valve, and it was fiddly and did "explode" yeast goo out the top occasionally. I lost interest as a result. 

eww...looks like i'll be trying the baking soda/citric acid recipe

[Koi]

16 minutes ago, Brandy said:

I don't think there are many issues to worry about--this is a low pressure system, not compressed gas. It can be messy, but not dangerous. There are kits that make this easier, for about $20 on amazon (you supply the bottles and chemicals). I recently used one of those and had no issues. Previously, in another life, I had a home made diy one with no valve, and it was fiddly and did "explode" yeast goo out the top occasionally. I lost interest as a result. 

They days of DIY co2 bottles are away behind me, the last time I did it was at least 10-12 years ago. Since then I have moved more towards pressurized just to have it a little more control. Or at least relatively controlled in my eyes haha

[Marnol D]

I currently user (for my 20Long) the two bottle DIY setup with the pressure gauges form amazon that were like 20$ (i have two of them one works great by itself the other needed a closeoff valve for help) I run my setup off of Dr. Pepper bottles (they seem to be thicker than other brands) and ive changed them out every so often (usually if i get my hands on 2 more bottles and its time to remix the mixture) I have had the bottles hold over 20PSI (according to the gauges) and be fine.  I use 1 to 1 baking soda to water mix the is fed by a 1 to 3 mix of citric acid and water. I close the valves nightly. You can also "halt" the mix by moving the feeding tube from the solution of the citric acid bottle so it doesnt feed the baking soda bottle.

[WaterPig]

For my 20 high, I'm using a CO2 reactor kit from Amazon. It came with a diffuser, solenoid, pressure gauge, etc. Every 2-3 weeks I clean out the reactor, mix up some baking soda + citric acid powder + water, and away I go. After a lot of experimentation with diffusers, I found the simplest solution was just to insert the CO2 output line into my powerhead air intake (in my case an AquaClear 20). Surprisingly, the powerhead was able to chop up the gas into fine enough bubbles that will float around my tank. For a demonstration, see the YT video "Best Co2 Diffusers Reviewed + Explained". I'm aiming the powerhead across the back wall of my tank. Combined with the circular downward force from my HOB, it seems to spread the bubbles around the tank reasonably well. I found that a lot of getting DIY CO2 to work for you is in getting the bubbles to distribute properly so they actually land on your plant leaves. If you have uneven flow, some plants will get all the CO2 and/or some will simply rise to the surface and escape.

As for not gassing your fish, make sure to get a drop checker so your don't run too much CO2 during the day. Get everything you have on a timer. I'm using the "Kasa Smart HS300 Plug Power Strip" which lets me individually program timers for everything in my tank (air pump, CO2 solenoid, filter, heater, lights, powerhead). That power strip is probably the best purchase I've ever made in terms of tank equipment.

I've got the lights on for 8 hours a day + 1 hour on each side for ramp up and ramp down (fluval 3.0). At the start of the ramp-up, the air stone goes off (Aquarium Co-op pump + air stone), the powerhead comes on and the CO2 comes on. At the start of the ramp-down, the process reverses (with an hour gap in between the CO2 turning off and the air starting). In theory, all of this should help the plants get O2 and night and CO2 during the day. Through the magic of the powerstrip (and the fluval light app), I don't have to touch anything to make all this work.