Tetra C02 Optimat

[cooper1973]

can anyone help me i have the tetra co2 opti. now i have been using it for about 2 weeks now and i have also got the jbl permanant co2 test kit too and last week i was using the c02 and the test kit has gone up to the yellow and i done a water change to bring co2 bqck down. i then set the test kit up again and been using co2 and noticed this evening that its gone back up to yellow again. could i possibly be using to much co2 to make this give this reading. where should i fill the tetra co2 cylinder upto or should i change this for something else?

 

[tom_os]

fill it up just before the lights come on

 

[cooper1973]

fill it up just before the lights come on

hi thanks for you fast response..............do i fill the cylinder right up or just to the lines on the cylinder which is about an inch from the top

 

[tom_os]

im not sure i dont have this system. i just know the plants need co2 when the lights are on so therefore you inject co2 just before lights come on