Why are plants closing up

[jerman]

Why is my ludwigia and rotala closing up during the last hour of my light period. The rotalla is new and I'm trying to get it settled, but the ludwigia is rockin and I just trimmed it back 50%.
Are they reaching for more light or actually closing up. My tank is a 50 gal corner tank with 155watts of CF wih DIY CO2. Its a deep tank at 24 inches.
I'm workin on m my photo skills too.
All my tank parameters are good.
Thanks

 

[czcz]

They've just stopped photosynthesizing. You may find it interesting that if you change the lights off time, and after keeping it consistent they will still close before the new lights lights out time. Tips will also close after too long a lighting period, as if the plants are saying they've have had enough. You have two of the better plants to play with for this.

Your color, expecially on R. rotundifolia, is very nice.

 

[jerman]

Thanks, Decrease lighting time?

I'm gonna try and decrease the light period by an hour and see if they still do it. Beside decreasing the light a bit willl help cut back the green haze algae build up on the front glass.
Thanks
J

 

[malkore]

what's your PO4 at? low PO4 usually leads to green spot algae on the glass walls and rock work.

like czcz said, the plants are just going ot sleep. many terrestrial plants, especially flowers, will close up at night as well. no sun, so no need to have their petals/leaves un-furled to capture the light...better to pull them in to protect against damage.