Blog Posts with Giveaway: A Place to Ask Questions Like About Blue Light

[ArtPays]

I so appreciate how you're always thinking about how to keep us informed and educated!  A loving suggestion in regards to the blog posts that I've now started to read for the giveaways ("PICK ME, PICK ME!!!" - - How fun!): I always have a question when I'm not distracted by just enjoying watching your videos. Might one of the following options be possible? 1) A place to ask questions at the end of the article. 2) A LINK to a place to ask questions (specific to the article, with no hunting) at the end of the article. 3) A place to list questions for the next time you cover the same topic. 

Re: "A Matter of Light and Depth," I wanted to know how keeping blue lights on at night, when I watch TV, affects fish or plants. I LOVE the calm blue light in the evening. Wish I could afford the blue shimmer of a Kessil at night!!! I know that they're sold for salted aquariums, but I absolutely love the calm affect at the end of the day. No one really addresses blue light's affect on planted freshwater aquariums. 

Final thought: Our pet stores don't even know their water's PH, let alone anything else. I've even found so many mistakes on signage. I wouldn't have known how much I love my stinkin' cute fish without you!  Thanks.  Trying to financially support you as much as possible. 

[Chick-In-Of-TheSea]

Tank lights feature blue light to simulate moonlight, and my fish seem to know that when the blue light is on, it's time to start settling down. They become way less active than they are when the white light is on.

However, fish need a period of complete darkness so they can sleep. They will not be able to sleep with the blue light turned on.

I find it useful to use white light during the day, blue light at dusk, and lights off during the night.  When I go to bed, the fish do too.

[ArtPays]

Thanks! Yes indeed! My fish seem to also love it. Do you find that adding a time with blue light is not ideal for plants, though?: i.e. They can't grow from/with blue light, but can't rest with it either (not enough time for respiration) ... all the while, algae CAN grow with blue light? (I'm not sure.)  I'm trying to figure out if I can leave white lights on for 10 hours (my normal limit to get red plants at peak color w/out algae growth) and then add 2-3 hours of blue at night for everyone's wind-down, pre-lights-out, good-book-&-coffee-next-to-FishKids time.  I guess I'm trying to figure out how blue light affects plants & algae.  

[Chick-In-Of-TheSea]

On 1/11/2023 at 1:05 PM, ArtPays said:

Thanks! Yes indeed! My fish seem to also love it. Do you find that adding a time with blue light is not ideal for plants, though?: i.e. They can't grow from/with blue light, but can't rest with it either (not enough time for respiration) ... all the while, algae CAN grow with blue light? (I'm not sure.)  I'm trying to figure out if I can leave white lights on for 10 hours (my normal limit to get red plants at peak color w/out algae growth) and then add 2-3 hours of blue at night for everyone's wind-down, pre-lights-out, good-book-&-coffee-next-to-FishKids time.  I guess I'm trying to figure out how blue light affects plants & algae.  

@Seattle_Aquarist and @Mmiller2001 are good w/ plants - let's see if they can answer this question.

[Mmiller2001]

I'm currently playing around with running my light for 11 hours and running a 1%, only blue, for another 4.5 hours. I have not noticed a difference honestly. 

[ArtPays]

Wow!  I can't do 11 hours: Get a touch more algae than the clean-up crew can stay on top of. BBA especially starts to grow.  Do you have plant fixtures/lights or standard lights?  Do you have a heavily planted tank? Thanks!

[Seattle_Aquarist]

On 1/11/2023 at 10:11 AM, Chick-In-Of-TheSea said:

@Seattle_Aquarist and @Mmiller2001 are good w/ plants - let's see if they can answer this question.

Hi All,

In October of 2015 the Greater Seattle Aquarium Society (gsas.org) invited Cara Wade a well know expert from Build My LED to Seattle for a talk on aquarium lighting and LED lighting.  It was very informative and the talk is in the digital library for GSAS members.  

First of all blue light is no different than of the other spectrum's of light in that plants (and algae) can utilize it for photosynthesis and growth.  Blue light, with the shorter wavelength, per watt it penetrates water more deeply than other light spectrum so in some ways it is more 'powerful' than say yellow or red light.  That said the determining factor for growth has absolutely nothing to do with light spectrum.....growth is determined by PPFD (aka PAR) or light intensity.  Below is a photo showing plant growth under various light spectrum with the light intensity (PPFD) equal for all spectrum.  Note that the growth is the same in all instances.

The bottom line is any light, regardless of spectrum, will effect plant (and algae) growth.  -Roy

[Mmiller2001]

On 1/11/2023 at 11:24 AM, ArtPays said:

Wow!  I can't do 11 hours: Get a touch more algae than the clean-up crew can stay on top of. BBA especially starts to grow.  Do you have plant fixtures/lights or standard lights?  Do you have a heavily planted tank? Thanks!

I use a Chihiros WRGB 2. I don't think my current setup would be considered heavily planted. 

You can take what @Seattle_Aquaristjust posted a bit further and apply it to longer photo periods. There's another measure called Daily Light Integral or DLI. It's a fancy conversion of PPFD and LUX to DLI, but the simple explanation is how many photons plants receive in a 24 hour period. So DLI can be altered by light intensity and duration. 

Let's say any light is on for 1 hour at 100% intensity, and just for numbers sake, 10 was our DLI. If I increase duration to 2 hours and drop intensity to 50%, DLI is still 10. Again, these are not true numbers, but just a very basic example of how it works.

The same number of photons are hitting the plants although the photo period is longer. So I'm using this strategy for the 11 hour photoperiod. I just keep dropping light intensity. I'm almost at my sweet spot and I'm right about at 50% intensity with this Chihiros.

Disclaimer, I'm not smart and could have told you wrong, but this is my very basic understanding of DLI.