The Planted Tank Forum banner
1 - 7 of 7 Posts

13,143 Posts
I have, I couldn’t really find anything for the planted plus model.
I have a "theory" or more of a system for ballparking PAR based on watts AT 18".
Nothing scientific, just more "fun with numbers" type things..
So here goes.. 1 PAR/watt at 18" for most simple LED strip lights.Sort of based on the fact that most are designed/driven similar and have similar speced LEDs w/ 120 degree lensing.
SEE post #38 for some background

Number can vary from like .9 to worst case 1.5 PAR/watt (twinstar outlier)
I was hoping for others to test and give me feedback on it but never really occurred.

So as to your orig. question.. Which size Nicrew and more importantly how many watts?

Nicrew confusing Plus Planted chart from evil bay

I'd have to chart it a bit but looks like watts is more consistent than lumens as to PAR
Lumens and it's cousin LUX have the weakness of any fixture w/ a lot of blue/red diodes will have low lux/lumens than PAR
due to by definition lux/lumens is green weighted while PAR is equal weighted across the 400-700nm bandwidth.
In other words actual lux/lumen photon counts would "miss" counting a bunch in the blue/red spectrum.
Not an issue with PAR.

@18 rough guess is 1/2 rated at 12"
25w 39par at 18"
1.5PAR /watt BUT those numbers from Nicrew may be a bit massaged. Would like more independent sources..
Regardless of if these numbers are correct you can still get a ratio of PAR at 12 vs 18" for various lights off thisas a comparison.

Obviously real measurements are more ideal and as better diodes enter the market it will change.

Hmmmm. Chihiros here holds to the 1PAR/1W at 18"

Nicrews have err weird numbers.
11W light w/ 63PAR at 15".. it's unrealistic in my opinion.
comes to about 50PAR at 18" and 11W.. 4.54 PAR /watt... Not likely unless lensed at less than 120 degrees.


13,143 Posts
The light itself is 16.3 inches with 15 watts. It does say 70 par at 12”.
Yea I can't explain it. It def punches way above it's weight class.
Even my own designs I can't get those types of numbers w/ 120 degree diodes.
Using secondary lenses is another story.

Some number crunching with data from a Nicrew Classic.
The "50" @ 18" was guesstimated from the curve shape.
2.7 PAR/ watt at 18"
Odd thing is the Seneye below isn't reporting "PUR" nor a decent spectrum chart.

Don't know what to say at this point.


Using that old chart few can punch into that territory and not at 11W, I think.


  • Like
Reactions: icurry408
1 - 7 of 7 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.