Are My Current Led Lights Enough Or Not

I have a 160L/42G tank (height 40cm/16in, substrate 8cm/3in), and I have built a DIY light system/scheduler, as well as its enclosing canopy.

The light fixture consists of 8 x 3W LEDs - 6000K, 280 lumens each. Its distance from water is around 8cm/3in. It runs for about 7hrs per day.

My plants are Anubias v.Nana, Bacopa caroliniana, Vallisneria spiralis, Java Fern, Helanthium tenellum, and Cryptocoryne wendtii.


I've read claims that we should be aiming between 10 lumens per liter to 40 lumens per liter (for light-hungry plants). Medium light plants would fall in the 20 to 40 range. Others prefer to go by the watt per gallon rule.

So in my case, I have 24 watts total & 2240 lumens total, which translates to 14 lumens per liter, and 0.6 watts per gallon.


Do you think the light that I provide is sufficient/insufficient?

 

I’m not familiar with the helanthium but the other plants will do fine in lower light. The WPG rule is outdated with led lights. Lumen per gallon is also hard to judge. A lot of people are going by par and pur, but average people won’t have the equipment to test it.
16” is not a deep tank and it’s easier/cheaper to get medium to high light in a shallow tank versus a 24” deep tank. I had a 3W green element light on one of my 24” deep tanks and it was way to much, the 3W led actually began to burn the leaf on my amazon sword and I removed the light. (Turned brown where the led was shining on it, was an oval pattern).
I believe you have plenty of light for your listed plants, just keep an eye on them and if the leaves start to look brown/burned you may have to cut the time back on lighting. Also a picture of you tank may help other members add more information.

 

How wide front to back is your tank?

 

Also a picture of you tank may help other members add more information

Thanks for your answer! Here's a photo I just took.

How wide front to back is your tank?

The width is 40cm/16in, same as height.

 

Well depending on the beam angle of the diodes, you may need to plant more in the middle front to back or raise the light so that the beam spreads front to back. There wouldn't be a PAR problem for those plants IMO. PAR is much more helpful in determining whether lighting is sufficient enough then lumens. PAR is a measure of how much light it's available for plants to use. Plants don't use much light in the green and yellow, but use mostly red and blue for photosynthesis. Yellow and green light is perceived as brightness to our eyes. So lumens really doesn't tell us much for light that plants use.

Btw, I like your tank The vals look a bit dark, but if they are growing with the light, they are doing alright. Stems at the back are a bit leggy, but are growing ok, so maybe trimming the tops seems replanting them in front of the lower stems might help it look fuller.