Dimmed Lights for Planted Aquarium


I'm almost certain that the answer is going to be no, but it doesn't hurt to ask.

I have a planted aquarium right in front of my bed, I love to see it at all hours. The thing is that I can't have the lights turned on as much as I would like to (to prevent algae), the lights are already on for 8 hours, but I spend the whole day in my room (online classes) and 8 hours isn't enough for me.

My question is, can I add a dimmer light fixture and turn that one on for a few hours when the other light is turned off? or do you think that even a dimmed light turned for a few hours on top of the other 8 is going to cause an algae bloom?


I think you should give it a shot. I have my lights on from when I wake up to when I go to bed, about 12 to 14 hours depending on the day. It works for me but I know I’m the outlier lol. I think it also depends on the conditions of your tank. Some of mine are completely algae free, some have little spots, and some are covered in various types of algae and Cyanobacteria. I think I’m just very lucky that my display tanks are clean.


I have never seen algae in my tank, I have 4 nerites, a few MTS (I never see them but I know they are somewhere in there ), and 3 Mystery Snails, and even tho I feed them high calcium pellets and some leaves from time to time, they spend the whole day eating everything the can get to (leftover food, leaves, etc...)

I think I'm going to give it a shot, if it doesn't work I can always go back.


Leave them on longer, if you get algae dial it back.

You could use an inline dimmer to decrease the intensity while increasing the time.


I have dimmers on all my LED tanks. I can define the light as a percentage of max intensity for each 30 minutes. So it starts at 07:00 at 1% of max capacity, slowly reaching a max of only 15% of max capacity at 14:00, then slowly returning to 1% at 21:00. I have no detectable algae; also thanks to the fact my tanks are very heavily planted and have shrimp colonies in it. You can even choose to have a break around the afternoon and have the lights completely out and rely on ambient room light. I only use shady plants that also grow with just room light.

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