Light settings for Chihiros WRGB II 60 cm on 80cm (20 gal) long tank

[umi]

Hi guys, I'm having some issues with recurring algae growth on my tank glass and plants. I clean it one day and its back within the next 3. I'm starting to get pretty tired of it and want to avoid algaecide, so I want some recommendations on RGB light levels.

The lights a bit on the shorter side for the size of the tank so I've been running it at 80/60/60 RGB but I've been hearing varying opinions that its best to run 45/30/30 and lower, or that its better to run it at higher levels so that theres a high enough PAR value at the substrate. I've tried running lower but the tank just seems so dark.

I'm trying to have a dwarf hairgrass carpet so I don't know if they'll get enough light. At the same time, I'm also trying to grow red plants such as ludwigia super red, alternanthera reineckii rosanervig, and rotala narrow leaf sp. red. 

Some additional information, I do have CO2 running and have the lights on from 9:30AM-7:30PM with a half hour taper on each end. 

What general RGB levels would be recommended for optimal carpet and red plant growth while minimizing algae growth? 

[Pepere]

I have 2, 29 gallon tanks with Chihiros wrgb 2 pros 60 cm on them.  I have CO2 running a ph drop of 1, and fertilize diy mixed dry salts weekly after 75% water change.

 

I run  90 red, 70 green, 105 blue.

 

granted it is a 29 with more depth, so you would likely wan5 a bit lower, but I am not so sure you will find a magic light setting to eliminate algae.

I found personally, issues such as suitable fertilization, improving flow, manual removal, water changes, keeping tank conditions consistent and stable, tank cleanings, pruning infested growth, substrate cleaning etc. helped me get rid of algae.

 

”Plants that are growing robustly produce an array of anti-microbial chemicals; various  alkaloids, terpenes, phenolics, as a defence against pathogens and microbes. Plants will prioritize defending the valuable new leaves first, as these newest leaves are optimized and adapted to the current environment and contribute the most. Leaves have limited plasticity, so older leaves have limited ability to be adapted to new environments. Parallel to this, the plant may draw reserve energy and nutrients from older leaves to fund the growth of new leaves. The bigger the change in environment, the more we see this in play. As the plant abandon defending the older leaves, metabolites leak from the leaf margins and attract algae to spawn.

 

While the exact mechanism of plant defences and algae triggers can be complicated, the useful observation is this: Old or unhealthy leaves attract algae, while robustly grown, fresh new leaves are algae resistant. While hobbyists have been obsessed with correlating particular nutrients or parameters with algae growth, the far more common trigger for algae in most tanks is unhealthy/old leaves which plants have given up defending. Plants sacrifice old growth when they are under adaptation stress or not getting their needs fulfilled.””

 

from a page on the 2 hr Aquarist website

 

That website is the site most responsible for my learning to overcome algae.