[hoppycalif]

One CO2 reactor that can be "turned off" at night is the Barr Internal Venturi design, http://www.barrreport.com/articles/41-diy-internal-reactor-great-yeast-co2-users.html. It allows you to turn it off because the CO2 bubble that builds up inside is allowed to leak out and bubble to the surface without adding much CO2 to the water. I used a couple of these for awhile and they do work well, but you have to like the "seltzer water" effect it gives to the water.

 

[hoppycalif]

Look at the drop checker sticky on this forum. Then get or make a drop checker to measure how much CO2 is in your water. When I had a 29 gallon tank, as I recall I used several bubbles per second of CO2. Don't pay any attention to the pH, just go by the drop checker. It isn't possible to say how many bubbles per second are "normal" for any size tank, because it depends on the reactor you use, or the diffuser, on the water surface ripple you have, and you do need some, the amount of water circulation you have all over the tank, how many tiny leaks you have in the CO2 system, the size of the bubbles, which varies by a huge amount, etc.

 

[hoppycalif]

As a side question, does overdosing with excel mess with a CO2 test kit numbers? I am using the red sea freshwater master test kit. I ran a CO2 test yesterday during the co2 cycle and the numbers I got were way out there (like fifty ppm according to my test- double checked the results). I have increased CO2 to one bubble per second over the last two weeks. My oto's aren't seltzerfied, and the ph seems to be holding fairly steady, so I think I may need to get a new test kit to double check the first. According to the PH/KH chart I can't be anywhere near that, so I trying to understand the wacky numbers. Any thoughts?

This is why you need to read the sticky on drop checkers. The explanation is in there.

 

[hoppycalif]

Hoppycalif, I am ploughing my way through all of you work on the DIY drop checker and it is a little thick (thirty pages... heavy....) Still trying to grasp all of it. (the chemistry not the DIY projects...)So I love DIY stuff, but it seems like I spend more on tools and equipment to save money than I would if I just bite the bullet and purchase a finished product. I just ordered a nifty looking set up from one of the site advertisers (greenleaf) that has the dual chambers with a green reference section and the exposed drop checker. Looks stylish. Hopefully that will do the trick.

That is the model drop checker I am using now, and it works fine. (Cal Aqua Labs).