DIY co2

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Hwom91

Gambusia
MFK Member
Sep 30, 2009
245
0
16
Oregon, IL
I made a diy co2 system, the 2l bottle system, and i have it running through an air stone. Now my question is do i need a bubble counter or should i disconnect the system at night? im kinda new to this and thought i would give it a try. this system is on a 10 gallon planted tank with a HOB filter. Thanks in advance for any info you guys and gals can give.
 
yeah use a airstone, ill chop up the bubbles and get the co2 in the water better than big bubbles riseing straight up to the top.
 
I recently set up a system similar to yours. Instead of an air stone, I would purchase a CO2 diffuser. I bought mine from my LFS for 8 dollars and it included a bubble counter. This will "chop up" the bubbles much smaller than an air stone could, and the smaller bubble size will then allow for more efficient diffusion into the aquarium water. As far as turning it off at night, it is recommended. During the day the excess CO2 that you pump into the aquarium is taken up by the plants as they go through photosynthesis, and they release O2 as a by-product, keeping everything in check. However, at night (when the lights are off,) no photosynthesis is taking place. Because of this the CO2 continues to build up and no oxygen is being released. This can cause your dissolved O2 levels to fall, giving you a pH swing, and causing your fish to suffocate. To counter this you could either add an air pump that turns on at night to give you extra O2 or you could simply turn off your CO2.
 
okay. Thanks for the info. I was thinking that having the airstone under my HOB filter would be enough to where i dont need to turn on the co2 at night. is this true? Or should i disconnect the co2 at night still? also how would i go about doing that so it isnt just leaking into my room?
 
Let me start by making 2 statements:
  1. Most people do not need CO2 (lighting is much more important)
  2. Pressurized CO2 is so much easier (easier to get the rate right, consistant).
That being said, I do still have 1 tank running DIY. It is a planted feeder guppy 30. There are a lot of videos on YouTube that may give your better info than I can communicate here. You will have to decide how efficient you want your system to be. As mine is on a 30 that is fairly heavily planted and has HO t5 lighting, I needed a powered diffuser to get the CO2 I needed.

First the assembly, a did a quick exmple for photos.
dropcheckercontiner.JPG
The first image is the container I used to make a drop checker. It is a Red Bull energy shot bottle.
dropcheckerassembly.JPG
Now for the tubing assembly you can use regular aquarium tubing or silicone based (CO2 resistant) tubing. I used regular as the CO2 will break down and harden the plastic, so it will all need to be replaced periodically. Drill your holes in the lids with a bit slightly smaller than the tubing and you can get a good pressure/friction fit. As stated before, the parts will have to be replaced periodically, so I don’t worry about sealing with silicone or anything like that. It will hold more pressure than normally produced with no sealant if you get your fits right. Make your line running from your CO2 generator (I assume you are using yeast fermentation as a DIY) to your drop checker long enough on the drop checker side to reach the bottom on the vessel. You can count the bubbles per minute to determine output. On the generator side, it should be as short as possible, just coming .25 to .5 inches into the bottle. Cut the tubing at an angle an pull through with pliars. The drop checker should be filled about 1/3 with clean water. Prevent any contamination. Most bacteria are hardier than yeast and will outcompete and kill it. The drop checker is important so you can judge how much CO2 is being produced and change your culture.
total CO2 assembly.JPG
The connector in my image should be replaced with a check valve. This will prevent tank water from being siphoned or forced by a pump back into the yeast vessel.
difuservessel.JPG
For my diffuser/reactor I wanted a powered setup that was small enough I could hide it in the back of the tank. I found a neat way of doing this with a bird feeder as in this image. Just drill a hole near the top and insert the output of a small fountain pump.
sponge.JPG
You will have to have some sponge in the open end to keep the CO2 in the reactor until it can be absorbed or much of it will just be blown out.
action shot.JPG
Here is my assembly in tank. I had to move it around some to get a good shot, but it is usually hidden. Inline just runs into the fitting on the pump output, or you could connect it to the top of the reactor.

Now for your other question. On or off at night depends on some factors:
  1. How much CO2 is being produced?
  2. Alkalinity of the water (buffer).
  3. How much surface agitation you have.
My pump is on a timer and shuts off at lights out. CO2 can drop pH significantly, so you will have to see for your self. If you are using a simple diffuser, them I'm guessing the system will not be efficient enough to really make a big difference as long as you have some surface movement. Having a method to check CO2 levels is important.


I hope this helps and sorry if I photo bombed the thread. I could not think of a way to communicate it any other way. If you have more questions just ask, but I am soon to be out of the DIY CO2 game. I have a small pressurized system in design now for this tank.:)

dropcheckerassembly.JPG

dropcheckercontiner.JPG

total CO2 assembly.JPG

difuservessel.JPG

sponge.JPG

action shot.JPG
 
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