Thank you, Oreo. It's not rimmed, but it has braces on the long sides, with three horizonal cross braces. I'll have a search for puck lights, I've got them over my shrimp tanks, so it would fit in. And also delight my theatre-lighting-designer husband 🙂.
ETA: Just another self-check ... The water volume once I have excluded the substrate is 300 litres, ish. And Google is telling me that I need between 20 and 30 lumens per litre for medium-difficulty plants. So I am looking for the set-up to be between 6-9k lumens. Is that correct or is my maths wrong? It seems like a lot of lights only measure in watts, which makes it all harder!
Technically you should be working in " par" levels ( ppfd) not lumens or watts.
50 par at the substrate is a typical starting point.
But....
If not par then watts. Start 1 watt/gallon or 1w/3.8 liters. Or 80- ish watts
If not watts then lumens.
Most modern white LEDs used run about 100 lumens,/watt. Your calculations would suggest a 60 to 90 watt light
Fairly consistent with the watts/ gallon estimate.
.As I state below a RGB light will not average 100 lumens/ watt but will not have less photons than a white light of the same wattage.
I believe you will get in less trouble by going for watts/gallon since it eliminates the " penalty" to RGB only led lights. They will measure less lumens than say a white led only light BUT they will have equal or more "par".
Plants only care about par which, unlike lumens, treats 400-700 nm photons equally
Lumens penalize blue and red.
Anyways most LEDs include dimming so really only a matter of cost in a sense. Buy as many watts as one can afford.
🙂
Now one catch is most of the above is based on 120 degree lensing and the smaller LEDs in the 1/2 watt class. Larger LEDs using tighter optics ( usually around 90 degrees.) do not fit the pattern. They will generally measure stronger at depth due to focus
.
So you are " euro braced" with clear bracing and no " proper " rim? That makes it difficult for pucks.
A "standard" puck style would be 3 AI Prime 50 watt at a non- budget cost of over $900US...
And no clear way to mount them.
And if you go to easily mountable lights the cost escalates..
The HMS system is not only for even more expensive lights but it is pieces..
Mount arms, bar, brackets and lights.
You may need to accept a bit of shading on the sides and use 48-60" type bars.
2 Nicrews like this is fine. Of course it's just like what you have only 2x..45 watts each. ip-67 water resistant.
