Trying to wrap my brain around something

[JJenna]

I'm trying to find a reference regarding the effects of duration and/or intensity of light in inhibiting algae growth. Does lowering the intensity of the light do more for inhibiting algae than decreasing the duration of light? I don't want to reinvent the wheel if someone has already written about this. Not looking for anecdotal information but scholarly, I've always learned  and maintained information better by reading.

[Mmiller2001]

It really comes down to DLI (daily light interval). Not a largely used term in planted tanks, but it's still relevant. You can have too short of a photo period regardless of intensity and too low of intensity even for a longer period. It really comes down to plant type, high energy or low energy tanks and husbandry.

My suggestion is a total of 8 hours at a medium to medium low intensity. Starting there will probably produce the best results. If you have high demand plants, a bit more will be needed.

[JJenna]

On 12/3/2022 at 1:45 PM, Mmiller2001 said:

My suggestion is a total of 8 hours at a medium to medium low intensity. Starting there will probably produce the best results. If you have high demand plants, a bit more will be needed.

This past week I upped my duration to 9 hours (1.5 hours of sunrise and sunset. 6 hours of white lights at 60%). No high demand plants only a few medium demand.

[Mmiller2001]

Wait a couple of weeks and see how it goes. Constantly changing parameters (including light) causes instabilities that algae can take advantage of. If it persists, and if you are staying on top of maintenance, then try lowering to 50%.

 

[Jungle Fan]

It's more than just duration and intensity of light that counts, you've also got to consider the quality of light, meaning how much red, amber, and blue is added in. With some lights you can control this. My Kessils allow me to up the red and amber which is what red plants need to display their color, while too much blue light can be a boon to algae. I got rid of my blue moonlights because of that. Also it doesn't matter if you have the greatest quality light, set at the right duration and intensity if any of the nutrients your plants need are missing you need to make sure you supply everything they need, if even one element is missing it acts as the limiting factor for your plants to be held back from using all else, and they are then out competed by the algae which they would otherwise handily beat to the punch. You also need to supply the nutrients in the manner the plants can absorb. Most stem plants, and epiphytes (Anubias, Java fern), and rheophytes (some Bucephalandra) will take up nutrients out of the water column  from liquid fertilizer, while Amazon Swords, and Cryptocoryne are heavy root feeders and need added root tabs. How high above the tank your lights are placed is another factor to consider depending on how deep into the tank your plants are placed and what the PAR rating of your light is at that depth.

For an easy intro here is a web site that also addresses PAR and PAS as measurements:

https://aquariumsphere.com/best-light-spectrum-for-aquarium-plants/

and of course:

https://www.aquariumcoop.com/blogs/aquarium/how-to-pick-the-best-planted-aquarium-light

https://www.aquariumcoop.com/blogs/aquarium/which-aquatic-fertilizer-is-right-for-you

https://www.aquariumcoop.com/blogs/aquarium/aquarium-co2-system

https://www.aquariumcoop.com/blogs/aquarium/co2-in-planted-aquariums

I hope this helps.

[JJenna]

On 12/4/2022 at 2:01 AM, Jungle Fan said:

https://aquariumsphere.com/best-light-spectrum-for-aquarium-plants/

This is a great start for me, thanks! I have a science background and would very much be into applying scientific principles in my aquarium keeping.