How Much Should My Light Be On?

[mrvillicus]

Hey everyone, probabl a simple answer and I guess its being asked a milllllion times but.....

How long should I have my aquarium light on? My tank is about 77litre/17 gallon and has some plants in it along with 3 neon tetra and 3 red fin columbian tetra (stock change soon)

 

[Judgejudy]

About 8-10 hours a day

 

[fluttermoth]

If you've got live plants, between six and eight hours a day.

 

[coldcazzie]

If you've got live plants, between six and eight hours a day.

^^ what she said.

6-8 hours is perfect for plants.

 

[mrvillicus]

thanks everyone, ive been leaving it on for 12 hours a day! I was worried that they would be in the dark too much

 

[Tonyb111111]

thanks everyone, ive been leaving it on for 12 hours a day! I was worried that they would be in the dark too much

I did the same as you when I was starting out, and at 12hrs you will almost definitely get algae issues. The advice on here is spot on.

 

[FishBlast]

thanks everyone, ive been leaving it on for 12 hours a day! I was worried that they would be in the dark too much

I did the same as you when I was starting out, and at 12hrs you will almost definitely get algae issues. The advice on here is spot on.

I'm still waiting on the green algae... I'm leaving my light on from 8 AM (or sometimes 10 AM) till 3 AM It's been going on for around 2 weeks now, but then again I never had algae on any tank, cycled or not. There's a first time for everything though...

 

[Tonyb111111]

thanks everyone, ive been leaving it on for 12 hours a day! I was worried that they would be in the dark too much

I did the same as you when I was starting out, and at 12hrs you will almost definitely get algae issues. The advice on here is spot on.

I'm still waiting on the green algae... I'm leaving my light on from 8 AM (or sometimes 10 AM) till 3 AM It's been going on for around 2 weeks now, but then again I never had algae on any tank, cycled or not. There's a first time for everything though...

How jammy are you

Mine was on 12 hrs for about 6 weeks, then all of a sudden, bang, stag horn and BBA everywhere.

 

[FishBlast]

thanks everyone, ive been leaving it on for 12 hours a day! I was worried that they would be in the dark too much

I did the same as you when I was starting out, and at 12hrs you will almost definitely get algae issues. The advice on here is spot on.

I'm still waiting on the green algae... I'm leaving my light on from 8 AM (or sometimes 10 AM) till 3 AM It's been going on for around 2 weeks now, but then again I never had algae on any tank, cycled or not. There's a first time for everything though...

How jammy are you

Mine was on 12 hrs for about 6 weeks, then all of a sudden, bang, stag horn and BBA everywhere.

Hmm, did you add anything during (mostly near the end of) those 6 weeks? Might have brought algae home with new plants and such.

 

[Tonyb111111]

thanks everyone, ive been leaving it on for 12 hours a day! I was worried that they would be in the dark too much

I did the same as you when I was starting out, and at 12hrs you will almost definitely get algae issues. The advice on here is spot on.

I'm still waiting on the green algae... I'm leaving my light on from 8 AM (or sometimes 10 AM) till 3 AM It's been going on for around 2 weeks now, but then again I never had algae on any tank, cycled or not. There's a first time for everything though...

How jammy are you

Mine was on 12 hrs for about 6 weeks, then all of a sudden, bang, stag horn and BBA everywhere.

Hmm, did you add anything during (mostly near the end of) those 6 weeks? Might have brought algae home with new plants and such.

Probably right, I added and removed so many plants during this time.

I think, but please correct me if I'm wrong, that it was my change from RO to tap water. Eh, I hear you say, but bare with me. My tap water is 5ppm phosphate and 50ppm nitrate, and I think all this extra nutrient with no CO2 set off the algae as it far more than the plants needed. Thoughts ?

 

[FishBlast]

Probably right, I added and removed so many plants during this time.

I think, but please correct me if I'm wrong, that it was my change from RO to tap water. Eh, I hear you say, but bare with me. My tap water is 5ppm phosphate and 50ppm nitrate, and I think all this extra nutrient with no CO2 set off the algae as it far more than the plants needed. Thoughts ?

My fish tank has been near the window (and older ones near a door that led to the balcony), so there was plenty of daylight for 3 months on new tank, YEARS on older ones, yet still no algae.
Then there's my tap: 5 ppm nitrate. The only way it could increase is by fish waste, but then again I only have 1 adult hoplo, 2 teenage swordtails, 3 fry and 2 apple snails. Not much bioload (yet). So it's probably around 20 ppm if my plants let it get that far (the ceratopteris sure seems to enjoy the new light and has something to grow on, so I guess it's eating the nitrate).
No idea how many phosphates available, but fish poop is constantly provided by my swordtails.
I also have a low tech setup (20 W light with full spectrum, a bit over 20 gal of water, plenty of tap water iron, no fertilizers, no CO2 except that provided by the fish and that pumped into the tank by the filter's air spray). So basically the light is low for the tank as it is.

 

[KISSfn]

12 hours got me in trouble with algae. Switched to 8 and it's getting much better.

 

[Crossfire]

Uhhhh.....I have my lights on from 7am to 7pm......I've never encountered an algae problem....ever.....at least, for now

 

[Tonyb111111]

Probably right, I added and removed so many plants during this time.

I think, but please correct me if I'm wrong, that it was my change from RO to tap water. Eh, I hear you say, but bare with me. My tap water is 5ppm phosphate and 50ppm nitrate, and I think all this extra nutrient with no CO2 set off the algae as it far more than the plants needed. Thoughts ?

My fish tank has been near the window (and older ones near a door that led to the balcony), so there was plenty of daylight for 3 months on new tank, YEARS on older ones, yet still no algae.
Then there's my tap: 5 ppm nitrate. The only way it could increase is by fish waste, but then again I only have 1 adult hoplo, 2 teenage swordtails, 3 fry and 2 apple snails. Not much bioload (yet). So it's probably around 20 ppm if my plants let it get that far (the ceratopteris sure seems to enjoy the new light and has something to grow on, so I guess it's eating the nitrate).
No idea how many phosphates available, but fish poop is constantly provided by my swordtails.
I also have a low tech setup (20 W light with full spectrum, a bit over 20 gal of water, plenty of tap water iron, no fertilizers, no CO2 except that provided by the fish and that pumped into the tank by the filter's air spray). So basically the light is low for the tank as it is.

In my case, my lights are reflected T5s approaching 2wpg, so I guess they were getting to much. When using tap water my nitrates would be there highest immediately after a water change, which is why I am now back on RO, plus my fish seem to prefer this

 

[FishBlast]

In my case, my lights are reflected T5s approaching 2wpg, so I guess they were getting to much. When using tap water my nitrates would be there highest immediately after a water change, which is why I am now back on RO, plus my fish seem to prefer this

Then it must be the excess nitrates.
Though I think also recently store-bought plants can bring the problem regardless of lighting / nitrate and you'd get an algae invasion. I saw at Carefour mall's pet shop a lot of plants covered by some black hairy algae (must be BBA), I was like "What? They have low light, their plants are damaged beyond belief, they got some beard growing on their leaves too... and this guy's telling me that I should get a special light meant for plants for 30$ when mine are in better shape?" So again I didn't buy anything from their shop. Every time I go there, stuff is expensive or damaged AND expensive LOL.

I hope my recent addition Java Fern won't bring anything in, I chose the best looking plant from my favorite shop (other ones had some areas eaten by a snail) and only problem mine has is that one leaf has a black tip and a few patches on the edges, probably didn't get enough food in the shop because they were housed only with snails and depended on ferts. It's already growing some bumps underneath, I may be getting baby ferns from it within a few weeks.

Btw it says that mine is T8 18W 6500K, finally got to read the rest of the stuff on it. Still low, but at least the plants seem to like it, since they're growing like mad now.