Lighting - How Many Hours/Day?

[Jweiner]

What is the appropriate length of time that an aquarium light should be on each day for a freshwater tank that does not have live plants in it?

 

[Fresh2o]

Not sure if there is an appropriate number of hours for this. The fish need several hours of darkness for downtime. Too many hours with the lights on may lead to various types of algae to develop. I believe 6-10 hours is pretty typical.

 

[skrapeNKA]

Anywhere from 8-14 hours would probably be just fine, though YMMV. If you want to get super sciencey, figure out how much full sun falls in the region your fish are native to (it's probably gonna fall in that range, though). I run mine for 9 hours a day (plants) because if I have them on much longer it seems to lead to green hair algae. Though I'm sure my shrimp and snails are upset there isn't any more of the stuff, I don't want to look at it!

 

[flchamp89]

Hard to answer the question without lots of info. Plants species, dose schedule, co2, and par data.

I run my stingray 7 hrs on my 10g. 4 on 3 off 3 on. Its generally better to have a break in photo period and also start with less hours and gradually monitor and add time.

 

[Coursair]

I don't do more than 8 hours or I see Algae. YMMV

 

[MDDad]

I do 13...but I have low light levels (only the single tube cheapo hood from PetSmart)

 

[HooKooDooKu]

Think about two things: Nature and Algae.

In nature, fish see day light for about 8 to 14 hours per day (depending upon where they live and what time of year it is). So if you want to simulate the nature environment, you likely want to have the lights on for this amount of time at a minimum. Once read about an electronic control aquarium a guy put together that even went so far as to electronically bring the lights up slowly over time to mimic sunrise and sunset. After all, going from near total darkness to full light is a bit of a shock to the system for any of us.

But on the other side, if the tank is getting too much light, you are more likely to be growing algae. But algae growth is dependent upon more than just how long the lights are on. The amount of light also makes a big difference. So if you start to have algae problems and you already have the lights on for less than 8 hours per day, then you might need to look into reducing the intensity of light. If you have a hood with screw-in light bulbs, use bulbs with a lower wattage. If you are using florescent lights and you don't need to light for growing plants, try a florescent light with a cooler color temperature (such as those labeled as 'soft white').

 

[Jweiner]

Thanks everyone!! I have a 20H with mainly microfish. I have an eLive LED light that has removable light "pods" so that I can add and remove lights from the strip. THe tank just looks so much better with bright lighting . I also have a few Kuhli Loaches which I know are nocturnal, so I don't want to confuse them with a weird lighting schedule. I'll do lights on from about 6am - 2pm and see how it goes. I feed my fish at 7am.

 

[skrapeNKA]

If you start to get algae with the lighting schedule you like, you could always add a nerite snail or two to mow it down. I was having an issue with brown algae/diatoms (from the sand substrate I chose, I'm assuming) and added two nerite snails. Within a week they had scrubbed all my artificial rock, glass chunks, and driftwood clean of diatoms. After two weeks they had cleaned all the stuff creeping up from the substrate on the glass, and after about a month my substrate was spotless to a depth of 1/4" and they cleaned up all the plants; even the wisteria almost reaching the water surface. Now I stir my substrate up a bit every water change to give them a bit more to do, as they are WAY too efficient at keeping things clean. Mind you, that's just TWO snails; I'm a little concerned I may have taken home one too many for my tank!