I ordered the 18 inch 'DD' and the 24 inch 'DD' fixtures for my planted tanks from FINNEX and they arrived this weekend. I am very pleased with them! Just thought I would post some photos here (hope that they come through) for comparison with what I currently am using. They are supposed to be Medium light for a 10 gallon, but they really are surprisingly bright, IMO.
Below is a link to their PAR chart.
First off, I put the 18 inch (Ray II Ultra Slim LED DD) fixture on a 10 gallon tank that is one of my spare plants tanks. It is WAY over planted right now because I have a swap meet to take cuttings to. The tank sits in an East window and gets decent light in the morning, but loses a lot of light from mid morning on. I received the fixtures after 4 PM on Saturday and placed the 18 inch Ray II on the 10 gallon grow out tank. I returned an hour later and the pearling in this VERY heavily planted tank was absolutely outrageous! Also, compared to my other lights, it was like turning on runway lights. WOW.
The other fixture (24 inch Ray II Ulta Slim LED DD) is being used over a tub of plants that are being grown out for the same swap meet. I do have some photos for comparison of this unit over the top of a 20H which is also is way overgrown for trimming in 4 days for the swap meet. I have Rotala indicia draping over the water surface and a very dense clump of Riccia and Water Sprite that takes up over 1/3rd of the tank top on the right and is several inches thick. There is currently a CoraLife CF (2 bulbs each 6700K - 65watt) over the top of this tank. From the water line to the substrate measures 13 inches.
Right now, the overgrowth on the Rotala indicia drapes over all but a 5 inch by 11 inch triangle on the top. Please keep this in mind when you look at the photos. The larger CoraLife unit has TWO tubes (6700K - 65 watts each) and spans twice the width of the Finnex unit. That being stated, I am very pleased at the light hitting the bottom of the tank and again, the immediate increased pearling.
Below is a photo of the top of the tank and the LED fixture's position for these photos:
Below is a close up of the left corner using the CoraLife only:
Below is a close up of the left corner using the Finnex Ray II Ultra Slim LED DD only:
Below is photo of the Finnex ONLY illuminating the tank:
Below are two photos with BOTH units over the tank. The Finnex Ray II is in front of the CoraLife CF.
The first is a close up of the same corner with both fixtures on and also a full frontal view with both fixtures on. When the tank is pruned significantly, I will re-post photos and share the growth in the tank.
Thanks....comments welcome, as I am simply a hobbyist and do appreciate suggestions from others. This is a 'Grow Out Tank' for me. Plants get moved around between my 9 different tanks. Yes, the CoraLife CF fixture is older technology. I have had this one for almost 3 years now. The bulbs are about a year old. Still producing rich color in my plants. This tank has CO2 and receives at least a 50% water change each week plus fertilizers. Most of the fish are hiding, of course.