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Discussion Starter · #1 ·
Hello all! It's been a while since I originally made this account, and also since I last had an aquarium, but I'm in the process of setting up a 55 gallon aquarium that I'd like to plant low light/low tech and wondered about using a grow lamp I have for my succulents, and if it may be worthwhile for my tank instead! Figured I'd see if I could "repurpose" before spending the money on new lights.

I don't have an awful lot of information about them, to be honest, which is why I'm hoping maybe someone can give me a ballpark idea if these would be useful in a 55g (21 inches tall plus a few for gap between the water surface). The wavelength appears to be great, and I have this chart from the Amazon page where I originally bought the lights, but it's a little... Unspecific as far as the data goes...

Plant Flowerpot Houseplant Green Yellow

Assuming that 87 umol/m2 is around the 16-20 inches depth mark, this light should in theory be plenty for low light, right? I'm hoping to forego CO2 if I can help it, but fertilizers will be supplemented as needed.

The 2 bulbs themselves are only about 6 inches by 2 inches in size, so the light spread won't be very much, I believe... But as far as viewing/aesthetics that doesn't bother me. I'm just unsure if it would be suitable for plants at 21"+ in depth. Any thoughts??

Oh, and here's the wavelength the product description offers:

Slope Rectangle Font Plot Symmetry

34 Posts
Discussion Starter · #4 ·
Since you have the lights already in your possession you should be able to get a very good idea if they will work. Use a lux meter or the lux meter app for a smart phone and take a reading the same distance from the light as your substrate will be (also position it so you take readings from off center to get an idea of what light will be like throughout the tank not just directly under the light). Then take that reading and divide by 80. This will give you a very rough approximation of par.

My biggest concern with a light like this is how well it will render colors. Ideally you want a light that will make all the colors look true to life as if it were being displayed under sunlight. This is basically impossible to accomplish but we can get close with high CRI lights (over 90+). I have no idea what CRI this light is but chances are if they don't mention it on the sales page its pretty low.
Thank you, I hadn't realized there were apps that could simulate a lux meter, I'll have to give it a try! I don't have a true lux meter at the moment but I'll have to look into that as well. It will surely be useful in the long run :)

CRI may be high but at the likely k temp of 4000- ish you are comparing it to an incandescent bulb not daylight
Spread is likey based on 120 degree beam angle.
Would not recommend it over an uncovered aquarium since you need to be fairly close to the water line. This is not restricted to this part. lamp.
Suspect usual watt rating games. Like bulbs are listed at 40w yet draw 20watts.
Using current "normal" l/watt diodes that's 100l/ watt
though the high red content will lower this.
I' ve seen actual lumens in reality for a real world 20w bulb (lusted as 40w) be as low as 500 lumens per bulb.
Lumens aren' t that important so on to the more important numbers.
It is possible that it 2 bulbs could reach about 50 par at the substrate in a 55. I doubt it is much higher though.

Longevity is questionable though.
Using relassy as an example they recommend no more than 5 hrs/ day to get a decent lifespan out of them. Fine print.

The electronics being in the shell is subjected to a lot of heat.

Other than that they seem perfectly useable.
Time and real measurements will tell.
I like to consider them " sprint" lights more than marathon lights, :)
Wow thank you so much for all of this information! Definitely a lot of things I was unaware of or hadn't considered! 😅 I think I'm going to invest in a simple but dedicated light, instead, just for the sake of longevity (and less questioning on how suitable it would be lol).
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