Light intensity vs duration

[chubasco]

I would like to know how long you folks light your tanks, day-to-day, and
what intensity (wpg and what kind) you are using, and if you've experimented with duration for optimum growth. I've seen some on other lists that use intense light for 8-9 hours, while I've been using 12 hours with medium-low cf lighting. Tank depth I think would come into play and those with medium light
would perhaps leave on longer than those with high light at the same tank
depth(?) Curious.

Bill

 

[jerime]

Re: Light intensity vs duration

In general, duration doesn't compensate for lack of intesity.
Think 10 hrs a day is enough.

I'm using 4-4.2 WPG and I think it's way too much. I'm planning to reduce intensity (getting too lazy for the frequent prunning) for most of the photo period and use full intensity only for the last 3 hrs...

 

[Ian H]

Re: Light intensity vs duration

In my 30" tank I have a 20w light that is on for 12.5 hours and Twin PC's of 39w on for 11.5 hours, giving me about 4WPG. The tank also gets about 2 hours of early evening sunshine (when it does shine in West Yorkshire ). I have plenty of duckweed, floating and emergeant plants at the surface.

This tank has no noticeable algae, just enough new algae to feed the army of shrimp and algae eaters. I do have to savagely prune the Mexican oak leaf plants, the trimmings are quickly filling my Trigon 350.

Ian

 

[jimjim]

Re: Light intensity vs duration

I've got a 120 gal(48"x24"x25"H) with 4x40w 48" flour and 2 x 36w 48"flour. Thats 232 watts/120gal (1.9w/gal), 10 hrs /day. but my few plants are pearling (no CO2) and evan tho the tanks been up about 5 weeks, I've already removed a 3gal bucket full. The kelvin range are 3500 to 10,000 and the fish load is light. very little alge, just some diatoms...Jim :gw

 

[Tom Wood]

Re: Light intensity vs duration

I have about 2 WPG when both lamps are on my 90 gallon, 1 WPG with just one lamp. I run a 12 hour day with one of the lamps off the first and last 30 minutes. I like the long day because of longer viewing, rather than any growth benefit. When I had them, it seemed to me that swordplants didn't care much for anything longer than 10 hours, but I may have been imagining things.

TW

 

[Vidar Vekve]

Re: Light intensity vs duration

I have a 61 g tank with 36w T8 and 2x54w T5. I put on the 36w for ½ hour before I put on the T5’s. I shut of the T5 when my Hygrophila Polysperma close the leaves which is about 10 hours after I put them on. Then I leave the T8 on for ½ hour.

Vidar