What's Classed As High Light?

[Smells Fishy]

I know the height of your tank is important, none of my tanks are very tall the tallest is 19inch. Is there a minimum amount of watts you need or what about led's? Currently on my tank I have 3 of the same hidom clip on led's that are 5w with 64 led's each, 4 being blue. Any idea what that would be classed as? Thinking about getting one of these https://www.amazon.co.uk/dp/B01FTH9Z1S?th=1 but I'm not sure if I should get this one which is 18w or the next size up which is 16w? That's confusing because shouldn't the longer length mean it should use more watts? I need to know this because I want to try out some red plants.

Cheers.

 

[alto]

From your link, LED used are smd's

Summary chart

In general 0.2watt LED can grow most plants in shallow tanks re this low intensity LED doesn't have much depth penetration - in a dense array such as your linked lamp, using 90degree lens rather than the 120degree would've improved PAR through water
If you calculate the lumen's 111 x 29 (# obviously depends on selected light) ~ 3200 , this doesn't sound too bad for low light plants (depending on water column height) BUT those lumens would be far more effective if 0.5 watt smds had been used in the build

 

[Smells Fishy]

I ordered it and it came yesterday. It's a pretty good light, a lot brighter than my other 3. It's a shame that the blue led's aren't really blue more of a purple and it was supposed to come with a 3 pin uk plug and it hasn't and lastly it says on the led that's its 5w-75w which I'm annoyed about because on Amazon it said the light was 16w. Piss takers, I'm still deciding what to do about this, I've emailed them and said I'm not a happy customer and still waiting for a reply.

 

[zozo]

In the days before leds were used, watts were kinda equivalent to the power of the light.. More watts meant for convenience stronger light.. Nowadays in the energy saving led era, this sum doesn't work anymore. LEDs are all about more power and less watts.. After all Watts only reflect power consumption per hour and not the ammount of light it radiates while consuming it.

Depending on the type of led used it can consume more power (watts) than the other but still give less light.

According to the specs from your link they have used the 5730 LED chip
https://www.12vmonster.com/blogs/pr...between-a-3528-led-5050-led-and-5630-5730-led
Which is classified as 45-50 lumen and consumes about 0.5 watt per chip. So if stated the fixture consumes 18 watt x 2 = 36 LEDs x 50 = approximatly 1800 lumen. 🙂

LED can have another con, which is temperatur.. The hoter they get the less light they give.. So if cooling isn't sufficient it will decrease in lumen output. If to hot for to long they will prematurely burn out. So the more lumen per watt a led can give the more cooling it needs to perform optimaly. I guess this temperatur issue is the reason why you commonly find only 0.5 watts led in common aquarium led fixtures which are all in the low light range. If you want high output, you realy have to look at Kessils etc. More expensive with build in cooling fan etc.

 

[alto]

From link,

LED Type: 2835 SMD

Commonly 0.2w 0.5w 1.0w - use watts listed for fixture & divide through by total LED number to estimate likely wattage of LED used
(Note that 0.5 w or 1.0 w hi-intensity CREE emits rather more lumens etc than the same wattage SMD )

 

[zozo]

From link,

LED Type: 2835 SMD

Commonly 0.2w 0.5w 1.0w - use watts listed for fixture & divide through by total LED number to estimate likely wattage of LED used
(Note that 0.5 w or 1.0 w hi-intensity CREE emits rather more lumens etc than the same wattage SMD )

Yup you are correct, it's the their Marine version of this light containing the SMD 5730. I misred this somewhere in the article. But lumen and watts are about the same per led..

 

[Smells Fishy]

Its just dawned on me that I've asked something that requires a complicated answer, or it seems that way with all the numbers and math needed.

 

[zozo]

Yes it is.. 🙂 Before the led the watt per gallon was a pretty good universal parameter. Tube lights were universali a bit performing the same in watt lumen ratio. 50 watt = x lumen per x gallon.. But tube lights beam light in 360°, a part down to the substrate and a part up to th ereflector, bouncing back from it towards the substrate. So here you have a loss, depending on the type of reflector and how clean it is.

A led beams light straight down in an +/- 120° angle, there is no loss upwarts and nothing needs to be reflected back. So 1000 lumen led will give much more bundled light downwards than a 1000 lumen tubelight will do. So it not compairable with these numbers, how it truly relates to eachother you would need both and measure it with a PAR meter.. And these are awfully expensive..

And the next thing is the led industry is far from evolving and keeps developing newer and beter ways to perform.. So we can break our head to find a formula to compair one with another, but in a few months it's not realy valid anymore. It keeps changing to fast at the time..