Hi, I'm starting this thread based on the following observation from my red tiger lotus.

Regardless of whether the light (&CO2) is on or off, I noticed that during:
a) day time (after around 7:30AM onwards) - all the leaves are in horizontal position (parallel to the substrate).
b) night time (after around 7:00PM onwards) - all the leaves are in vertical position (perpendicular to the substrate).

Although my tank is facing the windows, it is not getting any direct sunlight. The tiger lotus had been behaving this way since I first planted it about 4 months ago. The only thing I can think of is the plant has the capability to determine day from night, without being influence by the artificial lighting.

Anyone out there is also experincing this with your tiger lotus?

They are responsive (under water leaves, they have two types FYI_) to night time since they leaves can banged up in waves, currents etc.
Many leaves behave this way to some degree in aquatics and terrestrials.
Yours is likely arching for the light from the sounds of it.
Does not take much

Regards,
Tom Barr

That would appear to be typical, and not always indicative of light volume. I have way too much light, and they still repeat this cycle almost to the minute irregardless of output. Lotus are almost a nuisance in this house producing 6-8" leaves within days. Fortunately this helps with the excessive light, but is probably a direct result "OF" the excessive light ! HTH Prof M

Tom & prof, if plants are able to differenciate between day & night, would there be any impact on plant's growth in terms of lighting timing. Eg: having the lights on from 7AM to 7PM compare to 12 noon to 12 midnight (12 hours is just to simplying the calculation)? Not sure if it hurts the tiger lotus when having the lights on during it's "sleeping hour"

Provided no other light is coming into the tank during that time, no.

But if you have some sunlight(it's much brighter than you think), then it can cause the plants to stretch towards the sun during the 7am-12 noon time.

Regards,
Tom Barr

But it's sure a neat indicator for natural photo period isn't it ? Life is Dazzling !My lighting is already set to that appx. photo period, and is highly automated Muti-Spectrum to render sun up, and sun down through 13 phases on my show tank. My Growth tanks are on a straight 10 hour cycle, as are the quarantines.

I think it's just one more spectacular phenomenon to enjoy about planted aquaria, and perhaps a valuable tool for insight. Prof M

Thanks, Tom & Prof M. I'll play around with the lighting parameters & will update it here if I found something interesting.