Review on 🐠 3W Mini Aquarium Lamp with Timer - Submersible Green Light for Filter Area, Ideal for 5-55 Gallon Fish Tank, Pond Water Clarifier by Carol Fowler

As with most Revain purchases, I didn't know what to expect. The instructions are clear enough to show that the bulb does NOT go straight into the tank. The blue light kills the fish and damages the eyes. Light enters the filter. I had to take the sponge out of mine to fit it. You shouldn't see the light if properly implanted. I have a 9 gallon aquarium that is blooming with algae. The water was so green you couldn't see the back of the tank. I turned on this little lightbulb and set it on 12 hour cycles. Every day there were noticeable differences. On the third day it was transparent, and on the fourth - crystal. I took out the bulb, put it back in the box and will use it when I need it again. You don't need to keep it in the aquarium if the water is clear without it.