Timing For Solenoid Valve

[gizmo001i]

At the moment I have my solenoid valve connected up to my lighting timer. This means that the CO2 starts being injected as soon as the lights come on and stops when the lights go out. However, I have seen that some people have their solenoid valve on a seperate timer so that it comes on before the lights and turns off before the lights go out. I was wondering if there was any real difference in the effect of the CO2 with these two setups. Any views will be very appreciated. Many thanks
Ian

 

[Themuleous]

I think people have it coming on before the lights as it gives some time for the CO2 level to get up to the magic 30ppm. This probably means everything is primed and ready for the plants to start photosynthesising (sp? ) the instant the lights come on. Not sure what the benefits of it going off before the lights are?

Sam

 

[oldwhitewood]

I used to do it in that way but then I just banged the solenoid on the same circuit as my lights. I can see the logic behind doing it the way Themuleous pointed out and it might be quite cool to have everything automated to such a focused degree. I have a 4 tube T5 luminaire over my tank, I have two tubes coming on at dawn and all 4 on for the majority of the photoperiod, but it dips down to just two being on for the last hour. I do this because I don't want to cause too much stress to the plants suddenly having the lighting on at full whack, but to be honest I think that is just because it makes me feel better to have it that way it might not have any practical benefit.

 

[zig]

Recently i have been running a Ph controller on my tank, it works with a calibrated probe which is permanently in the tank so the Ph readings are very accurate, I use a solenoid which switches the CO2 off at night. This question was something that interested me when i first got the controller, i had always switched the CO2 on an hour before lights on (2.8WPG) without the use of a probe and assumed that this was enough to get me up to the required 30ppm level, well to my surprise this was barely enough time and in reality it takes about 1 1/2 hours, reading from the controller at over 1 bubble per second on a 40 galon tank.