[OSagent23]

Hello all,

I am trying to find the difference between LED lights such as the Finnex ray 2, 48" lights vs T5 Fluorescent bulbs for plant growth.

I am currently running 2 aqueon 48" fixtures. In total it's 4 T-5 6700k lights each bulbs puts out 38 watts. So 38 X 4 = 152 watts total. Am I wrong for thinking that this is enough light for a 75 gallon with medium to heavily planted tank?

Should I just use 2 24" Finnex ray 2 led strips? They seem brighter and are rated at 7000k.

My water parameters are 0 for ammonia and nitrite. 20 - 30 ppm for nitrate.
I use 1 Fluval 406 canister filter with filter floss, Purigen and ceramic rings in the canister.
I also have a Marineland Emperor bio-wheel 400. Carbon has been removed.

I also have a pressurized CO2 system that runs during light hours only. I also dose Seachems Flourish 2 times a week. My CO2 level is measured at 30 ppm. My PH is between 6.5 and 7.0 ppm. All my plants grow pretty well and never seem to die but I always here people talking
about how one can get amazing plant growth using LED's.
Is this true and recommended or am I doing something wrong?

Thanks for all your help in advance.

 

[VerdantGrotto]

Welcome to the Forum!
I'm afraid I won't be much help but I can tell you that I haven't had much luck with the few LED systems that I've had. Even some of the High dollar ones don't seem to put enough light out for anything other than low-light plants. Again, my experience with LED's is limited to a few Marineland light bars so I'm no expert. I actually removed my hoods and LED light system and converted it back to flourescent. As soon as I did, my plants started growing like... well weeds

 

[JDM]

I use a Marineland double bright LED fixture and am getting very good results (check the link in my signature, my planted tank thread). I don't know that you will be able to use CO2 with most LED though, they are not really for a high energy tank.

If you know the lux at the bottom of the tank you can directly compare any fixture. Even if you have the lumens you can calculate the lux, the only issue with tubes is that the reflector has built in inefficiencies that LED don't have making a lumen comparison not as absolute. Most LEDs will probably have the lumens as well as the lux rating for particular heights.

For reference, if you can get 2,000 lux at your depth you will make out fine with most plants excepting, perhaps, the really light needy ones. My results are with a fixture that is rated for 1,750 lux at 24" and my effective depth is about 20" down. That's an 8 watt output fixture. I calculated the effective lux for that depth but don't recall the exact number.

Jeff..

 

[Quantum]

a direct comparison using lux/lumens is only possible if the spectral distribution of the light sources are the same

four 48" T5s over a 75 gal is more than enough light for just about anything

edit: regular 48" T5s are 28 watts HOs are 54

 

[JDM]

a direct comparison using lux/lumens is only possible if the spectral distribution of the light sources are the same

four 48" T5s over a 75 gal is more than enough light for just about anything

edit: regular 48" T5s are 28 watts HOs are 54

6700 and 7000k were mentioned, pretty close.

Jeff.

 

[OSagent23]

Right now what I did as a test is I replaced one of the T-5 fixtures with a 7000k Finnex Ray 2 LED system. It's designed specifically for aquariums and plant growth.

Right now I have 1 T-5 fluorescent fixture with a 6700k regular white bulb and a 6700k Colormax bulb. Both bulbs are 28watts along with the LED and my plants are pearling. Something I have never seen them do which tells me the lights are perfect. I might even remove the other T-5 fixture and replace it with another LED strip just to see what happens there.
Posted via Mobile Device

 

[Reefing Madness]

The LEDs will put out way more light than you are thinking. They will put those T5s to shame, don't second guess this one.

 

[Quantum]

it may well be the case that these LEDs emit more light than the fluorescents, it's difficult to say just by looking at the numbers, comparing wattage between different types of light is generally useless as some are more efficient at converting electrical energy to light energy

but again, you had enough light before for most situations

 

[Reefing Madness]

The unit having reflectors or lenses makes all the difference.

 

[Quantum]

certainly a factor to consider, this may be the biggest advantage of LEDs, it seems likely that because of the way they are configured, a higher percentage of the light they produce will make it into the aquarium compared to fluorescents

 

[Reefing Madness]

Well, thats the difference between a good fixture and a bad one. Good T-5 units will have individual reflectors on the lamps, whereas cheap ones have one big reflector, that certainly helps, but it does not throw the majority back into the tank, like an individual reflector will.

 

[OSagent23]

The T-5 fixtures that I have are made by Aqueon. They each were about $80.00 on sale at petsmart when I first bought them. There is only one reflector vs the LED unit which has IODs that send light straight down instead of 360 degrees like a fluorescent light. Do you think this might also play a factor into it?

 

[Reefing Madness]

Yup.