I have the stingray on my 20 long and 10 gallon so I decided to get a clip on for my little three gallon tank and it is wonderful. I use it in addition to the light that came in the tank, but you could certainly use it alone. The picture below is just the stingray light on, no additional lighting.
For tanks like 20L and similar shallower tanks, this is a great light for planted freshwater and won't break the bank either. I use a few different ones throughout my fishroom and really like them.
I really enjoy the light the finnex gives off in my 10 gallon tank.
Looking forward to getting more!
I got one of these for my 40 gallon, the 36 in if I remember correctly. And when my girlfriend saw the difference between the Stingray and the bulbs lights on the 29 gallon her reaction was all I needed. Pretty sure that without looking at Corey's vids and the discount I would not have picked this one up.
I love my Finnex Stingray light. It makes everything look good The colors are brighter. It is light weight and easy to move when doing tank maintenance. The price was right also.