good diy co2 ppm

20-30ppm of C02 is the level to aim for, anything over 30ppm is not asorbed by the plants, from what I have read. Just make sure to keep your KH at 3+ so your PH does not drop to low.

my kh is 9

if I uncap my diy and change it to another tank will it still be producing co2 or do I have to remake once I uncap?

You don't have to worry about your KH.

Uncapping the C02 bottle does not make the solution lose power, once you recapp the bottle the pressure will build back up as long as the solution is still good.

alright that's good to know, how do usually prepare you batch? mine took 2 days to start..

I use 2 cups of sugar and 1 teaspoon of yeast (Fleischmanns) for my 20G tanks.

First I put the sugar in the pop bottle, fill the bottle half way with hot tap water and shake intil sugar is desolved. Then in a separate container I put the yeast, letting the yeast and sugar set over nite so that the hot water cools & the yeast warms up to room temp. Then I add cold tap water to the yeast and shake to mix, then pour the yeast into the pop bottle and turn the pop bottle over once to mix it all together. Then I add more cold tap water to the bottle, only to the top of the bottle label. I then let the bottles set over night and they are ready to hook up. This mix takes about a hour to start and last up to two weeks.

ok that's the same as me then thanks.

Here's the method I use:

http://www.gpodio.com/diy_co2.asp

I usually get CO2 production in a matter of hours but let it sit overnight to let it get over the initial burst of CO2.

Hope that helps
Giancarlo Podio