水草情迷

如果水草在日間有泡=放出氧氣,照理論晚上係咪應該都會有泡=放出co2呢?

Yes...........I saw bubble during night time..........
coz I turn on my light during night time.......hehehe..

我自己就會覺得唔會
因為開燈後,加上有打co2,再加上魚魚o的co2
o的草會吸收過多o既co2,o甘就會有過量o既o2
所以先會出泡
但係夜晚又會否有過多o既o2俾o的草進行光合作用中o既暗反應呢??
因為魚魚都要用o2嘛,點會有過多o既o2俾草草呢
不過呢o的都只係我自己諗,唔知係咪真.......

當然係不正確啦, 無論有光同冇光, 魚同草都會吸 O2 放CO2, 這叫respiration. 開燈見到氧氣泡, 係表示光合作用旺盛(當所有條件都好的時候), 但夜晚草放出co2時不會有泡, 是因為 (1)呼吸率不高, 不似開燈時因為有肥, 燈照等來提高光合作用, (2) CO2 是比O2 溶水, 因為化學結構令到O2不太溶水, 所以好多氧氣其實以泡泡形式出了水面而流失了

Hi! Sorry for not being able to type Chinese in this computer. In my understanding, the bubbles come up if the supply of CO2 is adequate and the photosynthesis run well so that O2 standard becomes naturally satuated (not "pushed up" by air pump for example). Although not formally proved, I think the O2 & CO2 proportion in water should be different to the one in atmosphere. Say, O2 ratio is higher than CO2 in water (???). (COs is higher than O2 in atmosphere on the other hand). In this case, I suppose that if CO2 could become saturated in water so that "CO2 bubbles" are formed, that could mean the CO2 to O2 ratio is higher which should be quite difficult to achieve, or if achievable, should be very dangerous to the beings in water. Is that true? Could anyone provide any comment?

I cannot totally understand what is your mean idea, maybe you can eliberate more. But some information I can give for your refence : in atmosphere (O2-21%, CO2-0.03%, N2-79%)

晚上也會有photosynthesis,不過respiratory rate已大過了
所以晚上是會放出co2的,不過不能像白天般聚積成"大泡泡"在葉上
始終respiratory rate不可能提升如photosynthesis那麼高

還有白天水草是不會放出co2到水中,因已立即被水草回收再做photosynthesis