Help with DIY CO2

[leoslizards]

I was considering adding a DIY CO2 system to my tank. I read a bunch of DIY plans and they all seem to be similar and easy to make. So I was thinking....

• º A 1 gallon plastic juice container
  º Airline tubing
  º Super glue to seal the airline tube to the cap (since I don't have silicone, it's safe for fish, I've used it before, not the Super Glue brand.)
  º Haven't decided on the diffuser yet. Either the DIY bell type diffuser or the Super Vortex Reaktor

Most plans I read where for a 2 liter soda bottle and most said it last about 2 weeks. So I decided to go with a 1 gallon bottle so it'll last longer. I was unsure of the sugar / yeast mixture though so I multiplied it by two. So I was thinking....

• º 4 cups of sugar
  º ½ tbsp (tablespoon or teaspoon, not sure which is recommended)
  º No baking soda needed since I live in Miami Florida and we have high PH and KH tap water
  º ¾ gallons of warm water

I was wondering if the ½ tbsp of yeast would produce too much CO2 and kill my fish, or should I just stick to the ¼ tbsp of yeast?
I was also wondering how I could measure how much CO2 is added to the water? I've seen people talk about CO2 meters but they sound expensive. I also saw someone talk about a DIY CO2 meter using regular ph measuring solution or something like that. Couldn't find much info on that topic. :?

Any help on any of these topics would be greatly appreciated.



P.s. Just in case you need to know, here are my water parameters and tank info.

I have a:
HOB Whisper Power Filter.
29 Gallon tank.
PH = 7.5
Nh3 = 0.6
GH = 220
KH = 110
NO2 = 0.1

My tap water.
PH = 7.6
NH3 = 0
GH = 100
KH = 50
NO2 = 3.3


Edited----------------------------------------------------------------------------
I just saw this sticky LOL.
How to make a reference KH solution for CO2 measurement

 

[Wizzard~Of~Ozz]

You shouldn't need more yeast, sticking with the 1/4tsp should be fine..

Also, try a glue gun for the seal. I found it worked the best since hot glue bonds very well and it stays relatively flexible.

 

[Satsumas]

I used a glue gun aswell, easy to use and it does bond very well.

 

[squawkbert]

Going from 2L to 1gal won't make it last longer, it will put out more CO2 for about the same amount of time.

Initial quantity of yeast shouldn't matter a whole lot either (although I'm about to test this for myself) unless you dump a ton in so it uses up sugar faster than it reaches some sort of population stability...

Your sugar recipe looks perfect in terms of ratios, I wouldn't sweat warming the water. Fresh yeast will perk up just fine in room temp water. I would tend to either age teh water overnight or add a drop of Prime or other dechlorinator to it.

If you have a good canister filter, you may want to just run the tube into the inlet, or shop around for a good diffuser (very fine bubbles) and place that low, below the filter's outlet so the water flow helps keep the bubbles in the water longer.

 

[Purrbox]

For a 29gallon tank you're going to need about three 2 Liter bottles to produce sufficient CO2 levels. You could also go with two 1 gallon jugs if you prefer. It's best to use at least two bottles so that you can rotate when you change out the mixture and minimize the CO2 fluctuations.

I'd go with the powered reactor over the bell as it should be quite a bit more efficient.

 

[Ketso]

There is a really good (I thought) article on DIY Co2 in my signature below. He goes into the whole process in depth/ Even goes through the different types of yeast you can use. Very informitive for me.

Hope it helps.

 

[Zezmo]

If you want to have your mixture last longer. Then you need to give the yeast some "food" besides sugar. A tablespoon of Dark Molasses and 1/4 cup of Protein Drink powder (whey protein powder works well, or any other "Muscle Blast" type powder). Also you want to maximize your water. More water keeps the alcohol levels from building up as fast. Yeast rarely uses up all the sugar, what happens is Alcohol levels get high and stall/kill the yeast.

Two bottles, or more, regardless of size, and started on alternating weeks will stabilize the CO2 output. Instability caused from one bottle may lead to algae issues (BBA).

When I had used DIY, the formula was - in a 2 liter bottle: 2 cups sugar, 1tsp Baking Soda, 1 tblspoon Molasses, 1/4 cup protein powder, a couple drops of declor and water all the way to 2 inches from the top of the bottle. I would typically get 4-6 weeks from that formula.

Yeast does not like warm water BTW, mixtures should be made with tepid water (neither warm nor cold - approx 95-105 deg)