Very long photo period

[NutZilla]

Dear all,

There's this guy that asked me to setup a 6 feet planted tank at his office lobby. The problem is he insist that the light must be on for at least 16 hours (only 8 hours off). My questions are, is there any problem that is likely to happen? And what is the precautions? Thanks.

[Tug]

I am assuming a planted tank with CO2 levels around 30 ppm. You could reduce the level of light and/or distance from the substrate. It is my understanding that light intensity is more important then duration. Keeping 30 micromol along the sediment is ample light.

Hoppy made this;

[Tom Barr]

Dear all,

There's this guy that asked me to setup a 6 feet planted tank at his office lobby. The problem is he insist that the light must be on for at least 16 hours (only 8 hours off). My questions are, is there any problem that is likely to happen? And what is the precautions? Thanks.

Then insist he find someone else to do the aquarium because the ecosystem will look like crap.
People can still see the tank, it just will not be lighted except for say 12 hours or less.
You will have issues with a client like this if you cannot convince them the needs must be met in the aquarium.

Tug's advice at 30umol or so, maybe even 25 might work.

Tank will still look much much better if you more light over a shorter time frame, the other option is put much of the plant biomass above the water line, shading the lower part.

[NutZilla]

I guess I better do some more convincing to reduce the requested photo period. Or maybe I'll put some bluish led to simulate moon light so people can still enjoy the tank instead of total darkness. Thanks.

[Gerryd]

I guess I better do some more convincing to reduce the requested photo period. Or maybe I'll put some bluish led to simulate moon light so people can still enjoy the tank instead of total darkness. Thanks.

Why not suggest/use the dimmable ATI fixtures? Than you can have a good plant photoperiod and crank down to a few % by zone for the other 8 hours or so.

Will that work?

Or, are the source of ambient light during 'off' hours that could serve for say 2-3 hours?

Even the tropics has ONLY a 12 hour light period.. 16 is just unhealthy, period IMO.