Light Break and Co2

[hmph]

Heard that lighting shouldn't be on for a stretch for more than 5 hours. My question is: Should CO2 be offed during the light break?
[:]

[PeterGwee]

Forget about the siesta...plants do best when all the stuff like light, CO2 and nutrients are available and a constant photoperiod of 10-12hrs.

[theodore]

Siesta probably doesn't benefit the plants in any significant way but I don't see any disadvantage to it either ... unless someone can kindly point me to a reference that suggest that plants are worse off when not given a constant photoperiod.

There is, however, one watchout when one does decide to implement siesta though - Many stem plants have a biological clock that causes them to 'open up' only 12-14hrs per day. E.g. various Cabomba, Luwidgia and Limnophila. So if one decides to give his/her plants 10hrs of intense light per day, have no more than a 3-4hr siesta break.

[eric_kclee]

I had good experience with light break. It may not be benefitial to plant but it does great harm to algae.

I had tried it and my 2 friends had tried it...all very signficant. However the other factors has to be first taken care of...good balance of nutrients and co2 and healthy plant.

I agree with 'siesta' (new term for me)

Don't let anyone convince you, try it out yourself..result will tell.....

Oh Yah! forgot to ans your question, too much trouble to control lighting and CO2 seperately...I on and off both together...Plant still grow well.

[bttay]

I learnt that if you turn off CO2 at night, you will need some time for the CO2 to come back to the desired level when the light is turned on. Then plants cannot benefit from it immediately.

However, if you leave the CO2 on 24hrs, there might be danger of CO2 poisoning at night if CO2 does not get out of the tank fast enough. This is quite possible if you use canister filter. Some use a timer to turn on air-stone at night to disperse CO2 into the air.

My cheap hang-on-back filter (though some don't recommand for CO2 planted tank) has managed to achieve some balance. I have pH of 6.8 in the day and 6.5 at night with CO2 all day long.