12000k

[Kajuki17]

I have a planted tank thats about 48 gallons filled with dying plants. I've been looking for a better lighting system and can only find bulbs that are in 12000k that are high enough wattage that are not acntic blue. So do these 12000k white lights work for plants?

 

[aaronnorth]

the best for plants i think is 4500k - 10 000k. Temperature isn't the main probobaly though, it will be either, not enough light, not enough nutrients or not enough co2. Can you give us theses stats please.

 

[Colin_T]

if 12,000K is all you casn get then they will be fine. They have a tiny bit too much blue in them but it is unlikely to be a problem.

 

[mibson]

I have 11 000k on my 90g and it really healps the plants down low in the tank (higher K value penetrates water better) but I did have a nasty brown algae problem if my co2 got too low...Now with co2 under control I have a very lush tank with no algae!

 

[RadaR]

Anything above 10,000K is basically for marine tanks. It's more blue in color. It simulates the colors that coral would get especially at depth, as blue is the last color absorbed by water.
However, colour spectrum is more important than the actual Kelvin rating.

 

[Kajuki17]

the bulbs are actually white. Moneys not the problem but there arn't any bulbs that are under 12000k with high enough wattage. I know light is the problem because only my low light plants such as wisteria and java fern are doing good. i am about to add my own diy co2 as soon as i get the higher lights. i add some nutrients every week.

 

[Colin_T]

Kelvin rating is the colour of the globe.
20,000K being primarily blue light.
5,700K being daylight with a white appearance but having red, yellow and a bit of blue.
4,500K being pink and commonly known as a Triphosphor, having lots of red light but not much if any blue.

 

[aaronnorth]

the bulbs are actually white. Moneys not the problem but there arn't any bulbs that are under 12000k with high enough wattage. I know light is the problem because only my low light plants such as wisteria and java fern are doing good. i am about to add my own diy co2 as soon as i get the higher lights. i add some nutrients every week.

It may look white to your eyes but it will only have a small amount of blue as it is only 2000k above the reccomended k for plants

 

[Colin_T]

I know light is the problem because only my low light plants such as wisteria and java fern are doing good.

A good way to tell if the plants are getting enough light is to watch hygrophilla species or ambulia. When these plants have had enough light they actually close their top leaves up to reduce the light getting onto them.
If you are concerned there isn't enough light you can leave the lights on for longer. Plants can have up to 16 hours per day.

 

[aaronnorth]

I know light is the problem because only my low light plants such as wisteria and java fern are doing good.

A good way to tell if the plants are getting enough light is to watch hygrophilla species or ambulia. When these plants have had enough light they actually close their top leaves up to reduce the light getting onto them.
If you are concerned there isn't enough light you can leave the lights on for longer. Plants can have up to 16 hours per day.

I wouldn't agree with 16hrs though, but thats just my opinion, i think 12hrs is good enough, if your lights aren't good enough then leaving them on longer wouldn't help would it? It would just cause algae issues, it could also stress fish.

 

[George Farmer]

12000K is fine.

10 hours photoperiod is fine. 16 is too much.

 

[Colin_T]

give the plants as much photoperiod as they need. Healthy plants actually produce a chemical that inhibits algae growth. Having the lights on for longer is the same as having higher wattage globes on for a shorter period of time.

 

[Themuleous]

give the plants as much photoperiod as they need. Healthy plants actually produce a chemical that inhibits algae growth. Having the lights on for longer is the same as having higher wattage globes on for a shorter period of time.

That's not strictly true, the 'allelopathy' theory has been largely disproved by packing activated carbon in the filter. This would remove any such chemical before it had an opportunity to work on anything. The key to preventing algae is to limit the availability of NH3 and to a lesser extent also NO2. These are 100x more capable of triggering algae than anything in the tank. Therefore, lots of healthy plants means little NH3 production. Couple this with a decent filter (over 3x the tank turn over per hr, 5x or 10x is better still) and there should be very little NH3 in the tank hence why there is no algae. Also, dead or dieing plants produce algae.

Healthy plants are the key to preventing algae.

Also, I dont necessarily agree that a longer photoperiod is equivalent to high wattage. A higher wattage will mean that plants are able to 'work' much harder for a given period of time compared to lower wattage. However, there is a limit to the time period over which plants can 'work' no matter what the wattage of lighting. Extending the photoperiod beyond that does little to help the plants as they become exhausted. It could even be detrimental as they do not get sufficient time to recover during the dark period i.e. lights off period.

Sorry I hope you dont think I'm picking on you, I'm not I promise, but triphosphor means the tubes produce light with three spectrum spikes, one in each of the blue, green and red wavelengths. A tube could in theory have a rating of 18000k and still be triphosphor. If is blue that means its producing more blue light not necessarily that it doesn't produce the other colours. The obvious exception being Actinic.

Sam

 

[TribeOfShroom]

I have my 125L tank lit by 2x 18,000K Aqua-glo bulbs and my plants love it. From what I've read in this thread and other threads, a lower light temp is suggested for plants. Why is this so?

18,000K seems to be perfect for my plants and I only have Vallis, java fern and frogbit

 

[Colin_T]

I have my 125L tank lit by 2x 18,000K Aqua-glo bulbs and my plants love it. From what I've read in this thread and other threads, a lower light temp is suggested for plants. Why is this so?

The higher Kelvin rating has more blue light in it. The theory was that freshwater plants came from shallow water. The shallow water allowed plenty of red light to get to the plants. Hence the tubes developed back then have lots of red in them. In reality plants use red light to grow tall and blue light to grow bushy. A combination of both and a bit of yellow light gives the plant a nice mixture for growing.
Another thing to consider is that over time the Kelvin rating of globes actually decreases as the globe ages. A globe that starts out with 18,000K might only be 16,000K after 6 months. And it might be down to 12,000K after a year. These numbers are still fine for plants. If you start with a 4,500K globe it might only be producing 2,000K after 6-12 months and that is not very good for plant growth.