Yet Another DIY CO2

[bizfromqc]

Got to work on my DIY CO2 for my newly setup 20G. This is your run of the mill DIY CO2 using plastic bottles.

Specifically, I used:
- 2l bottle for the generator
- 710 ml for the bubble counter/gas separator
- 2 check valves (1 between generator and bubble counter and 1 between counter and tank)
- Black silicone tubing

For the mix, I used:
- 2 cups sugar
- 3/4 tsp Lalvin EC-1118 champagne yeast
- 1 tsp baking soda

The whole thing goes to the in-tank DIY reaction chamber using a modified Hagen Elite Mini filter and an air stone in the filter/co2 reaction chamber.

Everything is hooked up and I'm waiting for bubbles to show up, maybe by tomorrow morning since the EC-1118 shouldn't take too long to kick it into high gear.

I'm sure this has been discussed and documented at great length before but in the rare case you haven't seen it or just want a quick look, here's where I took my information:

Using the Hagen Elite Mini as a CO2 reactor
http://www.aquaticplantcentral.com/forumapc/diy-aquarium-projects/44053-tiny-super-efficient-co2-reactor.html

The design of the CO2 system including the bubble counter aka gas separator
http://www.qsl.net/w2wdx/aquaria/diyco2.html

The yeast mixture recipe (I added a bit more yeast because of a lil' spill... don't ask)
http://www.aquatic-eden.com/2006/09/diy-co2-recipe-duration-vs-intensity.html

For those interested or who have read that far, I have attached pictures to the post so you can see what it looks like.

Now, the wait for bubbles begins...

[dan2x38]

You should get bubbles in just a few hours using that yeast. If you do not you might have a leak?

Here is a link to a 2 bottle system I used:

http://ovas.ca/forum/index.php?action=gallery;sa=view;id=1073

Why 2 bottles? You mix one up to start and the other plain water. After 5 days mix the 2nd bottle. This way every 10 days you change out the oldest bottle. To keep a constant CO2 level you must keep the production high. Waiting until they stop producing is not the way to go. I kept a 38g with some cool plants growing for years this way.

[pm]

As Dan has said it is suprising not to get bubbles within a few hours.  Perhaps it is taking a while to overcome the pressure needed for the check valves and depth of the tank.  

Take note, that the initial bubbles will not be co2, but the air in the lines, bottles, etc. so it will not really dissolve.  I say this as I used to use the mini elite filter for co2 on my old tank, and at first I was concerned as all the bubbles shot out of it appeared to reach the surface.  Than I thought about it and it made sense.  After a day or two the majority appeared to dissolve (they were mostly co2 and not just air).

The mini elite method worked great for me with a diy system.  The only negative I had is that the misting effect from the bubbles decreased the clarity of the water.  This isn't a huge issue as when plants are perling, the same thing occurs.

[bizfromqc]

Indeed, I do have bubbles this morning. Not a whole lot and sporadic but some bubbles.

I didn't have any last night because I literally posted the pictures MINUTES after I set up the whole system

Although, I have a feeling my check valves are pretty sticky. I tested them before putting them in-line by blowing air in them and it needed quite a good amount of pressure to get them to open. The airstone in the reaction chamber is a good 13-14" below the water line, that may not help either.

I'll reassess the whole thing tonight and adjust accordingly. I may get rid of the check valve between the generator and gas separator and just keep the one between the separator/bubbler and the tank.

Thanks for the tip on the bubbles, makes total sense to take a little while for the air (and not the CO2) to get out.

[touchofsky]

Another consideration is room temperature.  In cooler rooms, the yeast is not as active.

[bizfromqc]

My generator is sitting on the basement floor where it's basically laminate flooring on top of concrete, that could very well be a factor.

The yeast manufacturers claim that the optimal temperature range is between 15 and 25 degrees celcius but by looking at the chart, it does show a greater and more sustained production of CO2 at 20-28 degrees.

This is where I got the info
http://www.lalvinyeast.com/images/library/EC1118_Yeast.pdf

[bizfromqc]

You should get bubbles in just a few hours using that yeast. If you do not you might have a leak?

Here is a link to a 2 bottle system I used:

http://ovas.ca/forum/index.php?action=gallery;sa=view;id=1073

Why 2 bottles? You mix one up to start and the other plain water. After 5 days mix the 2nd bottle. This way every 10 days you change out the oldest bottle. To keep a constant CO2 level you must keep the production high. Waiting until they stop producing is not the way to go. I kept a 38g with some cool plants growing for years this way.

So basically start them 5 days apart and change the first one after the first 10 days. After that, change the "old one" (alternating) every 5 days to keep a constant flow. So each bottle gets changed every 10 days?

[dan2x38]

So basically start them 5 days apart and change the first one after the first 10 days. After that, change the "old one" (alternating) every 5 days to keep a constant flow. So each bottle gets changed every 10 days?

you got it... :-)

[bizfromqc]

HOORAY! We have bubbles.

Right now, I see one bubble in the bubble counter/gas separator every 5-6 seconds. I don't know what kind of bubble rate I should be getting since its pretty cold in my basement and the bottle is right on the laminate flooring but I'm still happy I don't seem to have any leaks in the system.

The airstone in the modded Hagen Elite Mini filter is doing a fantastic job at breaking up the bubbles and shooting up a fine mist throughout the tank!

Next step is hooking up a second 2L bottle and swap'em on a schedule as was recommended to me to get a constant flow going. I might also try to insulate my generator or find out some way to keep'em a bit warmer to get the production going.

I'll try to get a video tonight and post it on the forum...or maybe it's time I create a YT account...

[charlie]

  this reminds me of my entry to the CO2 world, i did so many varieties until i bit the bullet & went pressurised only to ask my self why i took so long
Any how try a container ( bucket) with water & heater or a baby bottle warmer.
Regards

[dan2x38]

Yeah 1 bubble every 4-5 seconds isn't enough. Warming it up is a must. You will really be wasting effort and yeast with that slow of production. DIY is tough enough to get stable & constant output without limiting it. Part of the chemical reaction involves it being warm.

How are you sealing the bottles? Attaching the hose, etc.? Using the exchange chamber method is excellent! It also prevents any crap ever getting into your tank along with the bubble counter. But it creates more spots for leaks. The hardest part of this is attaching the hose since plastic can't be glued. The other is defusing the CO2 into your tank.

Save up and get a pressurized system you will never regret it.

[bizfromqc]

Yeah 1 bubble every 4-5 seconds isn't enough. Warming it up is a must. You will really be wasting effort and yeast with that slow of production. DIY is tough enough to get stable & constant output without limiting it. Part of the chemical reaction involves it being warm.

How are you sealing the bottles? Attaching the hose, etc.? Using the exchange chamber method is excellent! It also prevents any crap ever getting into your tank along with the bubble counter. But it creates more spots for leaks. The hardest part of this is attaching the hose since plastic can't be glued. The other is defusing the CO2 into your tank.

Save up and get a pressurized system you will never regret it.

I will do as you recommended and go with two bottles on the 5 day and keep alternating replacing one of the bottles every 5 days to keep the CO2 up. If all goes well, with the current setup, that should bring me to 40 bubbles per minute with the 2 bottles. Might get more if I find a way to ramp up the temperature in my system (still thinking about the best way to accomplish that).

In any case though, any amount of CO2 that goes in my tank is better than no CO2 at all so it's got to be beneficial. As for the cost, its practically nothing, just my time and time invested in a hobby in time well spent in my books 

As for the details of the system itself, its all tight fitted now, no sealant was used anywhere. There doesn't appear to be any leaks anywhere but I'd probably like to find better quality check valves, something maybe requiring a little less resistance. Any suggestions or any good old valve should do the trick?

I have a couple of old Hagen Regent heaters (100w) knocking around somewhere so maybe I'll cook (no pun intended) something up to keep my generator bottles warmer.

[bizfromqc]

First step of version 2 of they CO2 system. Bottle #2 generator mixed and now hooked up. Next step, finding a way to keep everything warm(er).

[dan2x38]

Even placing the bottles above the floor with an open air space under it for a dead air space would be better than right on the cold floor. How about those little cheapo things that cheap your cup of coffee warm at work to sit on your desk? Connect it to a small power bar for safety. You could place the warmer under a board big enough to hold all the bottles. Do not want it to warm or it will deplete the yeast very quickly. There is something else you could try I use to use in Alberta - a battery blanket. They wrap around your battery then plug in to keep it warm for it to have more cranking power. They are not expensive either - might be the better option? They do not get super hot or anything like that.

[bizfromqc]

Both very good ideas, thanks for that.

I had thought about the coffee warmers but all the ones I saw were powered by USB and I don't have a USB connector or computer near by. The battery warmer sounds like a good plan, I'll look into it. Batteries are also encased in plastic so they're probably safe for my bottles, I'll look into it and report.

Thanks again!

[charlie]

Use the KISS - Keep It Stupid Simple 
a container of water put the bottles in it & use an aquarium heater to warm the water

[dan2x38]

Aquarium heaters for that size will likely heat things quite high. In that case the yeast will be used up very quickly. the temp. Should be close to 80*(f).  I found 78*(f) worked just fine. Even the smallest heater will be hard to keep low temps.

There are also the heater pads set to one temp. usually 78* (f). They are great for Betta tanks or other small setups. There are ones for reptile setups as well. Big Al's sells both of these for less than $20 each. I think Pet Smart carries them also. They have some very small ones so you can shop around too imagine varying prices of course.

[bizfromqc]

For kicks, I took a temperature reading in the water I used to soak my driftwood (was also sitting on the floor but on the bare concrete in the unfinished part of the basement versus the laminate where my CO2 bottles are) and it clocked in at 61 degrees.

Factor in a couple more degrees since they're now on a little stool and off the laminate flooring but I highly doubt they're anywhere near 80 degrees. I'm going to get a stick-on thermometer and put it on one of the bottles so I can stop guessing.

As it is now, with no heating, my bubble rate increased to about a bubble every 3 seconds.  I could swear it's a bigger bubble though  My water does look like seltzer water though.

[charlie]

Aquarium heaters for that size will likely heat things quite high. In that case the yeast will be used up very quickly. the temp. Should be close to 80*(f).  I found 78*(f) worked just fine. Even the smallest heater will be hard to keep low temps.

There are also the heater pads set to one temp. usually 78* (f). They are great for Betta tanks or other small setups. There are ones for reptile setups as well. Big Al's sells both of these for less than $20 each. I think Pet Smart carries them also. They have some very small ones so you can shop around too imagine varying prices of course.

I have done it years ago with a 50 watt heater set @ 72 deg F - no issues

[dan2x38]

For sure get your bottles warmer you can get greater output. Forget size of your tank but you want 1 bubble/second of better for great plants. If you have less than 30 gallons 2 bottles alternated out well diffused will get you some good growth if you have a decent light and fertilize well.

Good luck sounds like your on your way. It is true K.I.S.S. method works great but some times many folks shrug off some of the finer details about DIY yeast generators. With high quality yeast like your using, keeping things clean, nice and warm you will get good production. OH BTW you do not need a ton of baking soda. You want to raise the pH but it will only go to 8.2 with soda the rest is waste.