Lighting for 20gal Long

[codriscoll92]

I have a 20 gallon long tank and am trying to figure out how much lighting I should have. I'm not using CO2 and the plants are dwarf sag, limnophila sessiliflora, dwarf sag.

The tank came with a 8W, 900 lumen LED light which is on for 10 hours/day - and I'm unsure whether this is enough? The lid has a second slot so I couldget a second light (they make a "plant" version which is also 8W LED but I think has more wavelengths that plants can use). So this would bring me up to 1,800 lumens.

Edited February 3, 2021 by codriscoll92

[Fish Folk]

Well... we’re not great plant folk... so take this in stride... Lumens might not be the determinative lighting factor for you... but honest confession: we light our 20 gal long tanks with dirt cheap 500K LED shop lights from WalMart. And certain plants do very well! At the relatively shallow throw required by a 20 long, we do not necessarily need more or fancier lights. 

It sounds like your LED might be Ok. To help plants grow, maybe bury some root tabs and dose regularly with a liquid fertilizer. We use Aquarium Co Op Easy Green on certain planted tanks. You can always adjust your photo period depending on how things are looking.
 

Hopefully someone with better experience will chime in! 

 

 

[RockMongler]

I have a 20 long with java moss, anubias nana, hornwort, and hygrophila (and some small amount of duckweed I've been too lazy to exterminate).  I have the 30 inch Nicrew ClassicLED running for ~ 10 hours a day at 60% (it's sold as an 18 watt, 920 lumen lamp).  I had to turn it waaaaay down from when I first put it on, because having it at 100% for 10 hours (or more at first) gave me insane amounts of algae growth.  Now, I have some very very happy plants, and my java moss in particular looks amazing, and the hygro just has a tiny bit of excess algae where it gets a bit too close to the surface and the light.

So, you might be pretty good as you are!  Keep an eye on it, a lot of things plants do, they do slowly!