not sure how to measure my co2

[harmy4993]

im not sure how to measure my co2. i think its based off testing ph and kh but not really sure.

 

[SpeedEuphoria]

http://www.qsl.net/w2wdx/aquaria/diyco2.html

Theres a chart there 1/2 way down the page, itss not great but there are many around. Also I think many like using drop checkers better than the chart.
http://www.aquaticplantcentral.com/forumapc/diy-aquarium-projects/32100-diy-drop-checker.html

 

[Purrbox]

The chart works well as long as you don't have anything buffering your water other than KH. If you do, then you'll need to use a drop checker or another method to check. The best way to check for buffers is to leave a glass of water out for 24 hour or aerate it for an hour and then test for GH and KH. If the chart tells you that there is anything significantly different than 3ppm of CO2 in the water, then you have other buffers present and won't be able to use the chart.

 

[harmy4993]

so i get tap water let it sit for 24 hours. test the ph and kh and check the chart. then test my tank. do i subtract my tap water # from my tank #? or just straight tank #?

 

[harmy4993]

also one more question concernign co2. i found a reciepe called for 2 cups of sugar, 1/2 tsp of yeast and 1 tsp of baking soda. it didnt say what size container that was for. im using a 1 gallon jug. is that enough or does that sound like a 2 liter bottle size?

 

[Peyton]

That is the amounts for a 2 liter. Adding the baking soda is optional BTW. If you're dead-set on using DIY may I suggest that you be deligent in your changes of mixes. IME, they need to be changed at least every two weeks.

 

[harmy4993]

thanks. i dont plan on the diy co2 to be there long. couple weeks at most

 

[Purrbox]

so i get tap water let it sit for 24 hours. test the ph and kh and check the chart. then test my tank. do i subtract my tap water # from my tank #? or just straight tank #?

No need to test both your tap water and aquarium water, you're just trying to get a baseline CO2 level. You can use either one, as long as you aren't adding any pH adjusting chemicals to you aquarium (which you shouldn't be). By leaving the glass to sit for 24 hours or aerating it for an hour, you are gassing off any extra CO2 that may be present and returning it to ambient levels which is 3ppm CO2. If your testing tells you anything significantly different, then you know there are buffers present which are throwing off the pH/KH relationship so that you can't use the chart.

also one more question concernign co2. i found a reciepe called for 2 cups of sugar, 1/2 tsp of yeast and 1 tsp of baking soda. it didnt say what size container that was for. im using a 1 gallon jug. is that enough or does that sound like a 2 liter bottle size?

This is a recipe for a 2 Liter bottle. If your water is at all hard, then leave the baking soda out of the recipe or it could kill the yeast.

thanks. i dont plan on the diy co2 to be there long. couple weeks at most

If you are only looking at a couple of weeks, you'd probably be better off just waiting until you can implement the pressurized CO2.