Chihiros WRGB 2 Slim Over 75G?

[Harry Muscle]

Wondering if anyone is using a Chihiros WRGB 2 Slim over a 75G (48"x18"x20") tank? I like the look of these lights but I'm not sure if a single one would be enough light for medium/high light (aiming for around 75PAR at substrate). I think a single WRGB 2 (non Slim) might be enough but I really don't like the legs on them, the Slim just looks so much cooler.

Thanks,
Harry

 

[MartyK]

I'm using two normal WRGB 2's (one 60cm and one 45cm) over my 75G with the light resting directly on the top trim - no legs - and it can easily produce 150-200 PAR at the substrate with all channels at 100%. The coverage is pretty good but all of my plants are in the back two thirds of the tank so I have the light offset to the back. I do have an extra set of LED's in the front to eliminate any shadows but they're not really needed to get high light levels.

With only 40 diodes instead of 60 and with half of the rated output (2400 vs 4500 lumens), I would doubt the Slim fixture can deliver both high light AND full coverage on an 18" wide tank. If you only need 12" of coverage then maybe that is okay but if you need wider coverage then you'll have to raise the light and if you raise the light then you decrease the light intensity. I don't think you'll get even intensity across the whole width of the tank if you center the light unless you also raise it above the tank a bit.

I would definitely look for some reviews with actual in-tank measurements before committing to the Slim fixture.

 

[oreo57]

Wondering if anyone is using a Chihiros WRGB 2 Slim over a 75G (48"x18"x20") tank? I like the look of these lights but I'm not sure if a single one would be enough light for medium/high light (aiming for around 75PAR at substrate). I think a single WRGB 2 (non Slim) might be enough but I really don't like the legs on them, the Slim just looks so much cooler.

Thanks,
Harry

50- 70(top end) is a reasonable guess.
My "napkin" estimate would put it at 90 par at 18" light face to surface.
Est. real height is about 3(legs) + 20(tank) - 2(substrate) = 21"


Though you can use lumens between "like" units (in this case RGB only led) you can't really between unlike units like solid white led vs rgb.