is my tank too bright for plants?

Talk about your fresh water plants here
Post Reply
User avatar
olivena
Posts: 26
Joined: Thu Jun 30, 2022 5:22 pm

is my tank too bright for plants?

Post by olivena »

I've got a 20 gallon planted tank with a Finnex Planted+ 24/7 light. My Java Fern and Anubias are turning yellow, and I'm worried it's too bright. The light runs 8 hours a day. Should I cut the photoperiod or switch to a dimmer light?
User avatar
brookm
Posts: 12
Joined: Tue Aug 20, 2024 10:02 am

Re: is my tank too bright for plants?

Post by brookm »

What's your substrate like? If it's inert, the plants might be lacking nutrients rather than suffering from light stress. Also, check if there's any algae buildup, which can indicate excess light. I'd test nitrates and phosphates first before tweaking the light.
User avatar
FableMan
Posts: 7
Joined: Wed Oct 09, 2024 10:47 pm

Re: is my tank too bright for plants?

Post by FableMan »

olivena wrote: Sun Aug 03, 2025 10:42 am I've got a 20 gallon planted tank with a Finnex Planted+ 24/7 light. My Java Fern and Anubias are turning yellow, and I'm worried it's too bright. The light runs 8 hours a day. Should I cut the photoperiod or switch to a dimmer light?
Anubias and Java Fern are low-light plants. That Finnex is pretty strong for them. Try reducing the intensity or raising the light a few inches. Also, make sure they're not buried in the substrate, just attached to rocks or driftwood.
User avatar
Flowix
Posts: 19
Joined: Wed Oct 09, 2024 11:34 pm

Re: is my tank too bright for plants?

Post by Flowix »

I had the same issue with my Anubias under bright LEDs. Moved them to the shaded side of the tank, and they perked up in a week. Maybe rearrange your hardscape to create some shade?
User avatar
finnix
Posts: 8
Joined: Fri Aug 16, 2024 10:48 pm

Re: is my tank too bright for plants?

Post by finnix »

My cat knocked over my tank last week. Now I've got a mess to clean up. Anyway, good luck with your plants.
User avatar
olivena
Posts: 26
Joined: Thu Jun 30, 2022 5:22 pm

Re: is my tank too bright for plants?

Post by olivena »

Thanks for the tips, everyone. I'll try raising the light and testing my water params. Substrate is Flourite, so it should have enough nutrients. I'll update in a week.
User avatar
brookm
Posts: 12
Joined: Tue Aug 20, 2024 10:02 am

Re: is my tank too bright for plants?

Post by brookm »

olivena wrote: Sun Aug 03, 2025 2:09 pm Thanks for the tips, everyone. I'll try raising the light and testing my water params. Substrate is Flourite, so it should have enough nutrients. I'll update in a week.
Flourite's great, but it doesn't release much nitrate or phosphate. You might need root tabs or liquid ferts if the issue persists after adjusting the light.
User avatar
FableMan
Posts: 7
Joined: Wed Oct 09, 2024 10:47 pm

Re: is my tank too bright for plants?

Post by FableMan »

Yeah, Flourite's more about structure than nutrients. I dose Thrive twice a week in my low-tech tanks. Keeps the Anubias happy without causing algae.
User avatar
Flowix
Posts: 19
Joined: Wed Oct 09, 2024 11:34 pm

Re: is my tank too bright for plants?

Post by Flowix »

brookm wrote: Sun Aug 03, 2025 3:31 pm
olivena wrote: Sun Aug 03, 2025 2:09 pm Thanks for the tips, everyone. I'll try raising the light and testing my water params. Substrate is Flourite, so it should have enough nutrients. I'll update in a week.
Flourite's great, but it doesn't release much nitrate or phosphate. You might need root tabs or liquid ferts if the issue persists after adjusting the light.
Second this. I use Easy Green in my 20 gallon, and the plants are thriving. Just go easy on the dosing to avoid algae blooms.
Post Reply