Best Color Light To Grow Algae?

Yeah that's right, I want algae! Anyone wanna give me some of theirs?

Lol in all seriousness, I'm trying to grow some saltwater algae in a 1/2 gallon jar where I am raising amano shrimp larvae. My other tanks are freshwater, and they get plenty of unwanted algae, but I can't seem to grow any in the saltwater jar so I'm going to go to 24hr lighting for a bit. I have this little LED that does red, green, blue, or white light. Which color should I set it on for the best algae growth? I've read from a few sources that blue does something to the iron in the water that allows algae to use it more easily, but I've also heard that the red/white end is better for photosynthesis, so idk what to go with. (There are no other plants or anything in the jar, just shrimp larvae).

Edit- is it even possible to grow any algae in an isolated jar? I know in freshwater tanks the algae can come from the tap water and grow, but there wouldn't be any saltwater algae in the tap water, right? And I'm not bringing in anything from an established saltwater tank that would have algae... lol is it possible to grow it from nothing?

 

You'll be best to get some cheato. The best lights for growing algae (we do it in fuges) is those pink grow lights.

 

Well.... just like FW, Saltwater algae won't grow without a food source. Is anything in the jar producing ammonia, or is there any source of phosphates or nitrates? Algae usually starts showing up in a saltwater tank right at the beginning, during the cycle. We'd have to have a little more info on the jar's set up to say for sure, but it sure shouldn't be hard to grow algae. Is there a cycle in the jar? Is there any type of flow? I'd imagine not much, but instincts say that even larvae need some type of flow if only to oxygenate the water, so perhaps an airstone?

Algae does just show up on it's own, as long as some nutrients and light is provided. Chaetomorpha is a macro algae that a lot of saltwater tanks grow in a refugium outside the tank. It is a method of nutrient export, (it eats up nitrates, keeping that level very low for reef tanks), so will outcompete other nuisance algae types, like GHA.

You'd want a light that produces a good spectrum for growing plants, so around 6700K or higher. This is the light that I keep over my refugium, and it does a very good job at growing cheato.

 

Well.... just like FW, Saltwater algae won't grow without a food source. Is anything in the jar producing ammonia, or is there any source of phosphates or nitrates? Algae usually starts showing up in a saltwater tank right at the beginning, during the cycle. We'd have to have a little more info on the jar's set up to say for sure, but it sure shouldn't be hard to grow algae. Is there a cycle in the jar? Is there any type of flow? I'd imagine not much, but instincts say that even larvae need some type of flow if only to oxygenate the water, so perhaps an airstone?

Algae does just show up on it's own, as long as some nutrients and light is provided. Chaetomorpha is a macro algae that a lot of saltwater tanks grow in a refugium outside the tank. It is a method of nutrient export, (it eats up nitrates, keeping that level very low for reef tanks), so will outcompete other nuisance algae types, like GHA.

You'd want a light that produces a good spectrum for growing plants, so around 6700K or higher. This is the light that I keep over my refugium, and it does a very good job at growing cheato.

My source of nutrients would be my Amano larvae, as well as the spirulina I will be feeding them (until the algae grows in, if it does). I do have an airstone for circulation, other than that the jar is bare. I don't think I need a specific type of algae, the larvae should be happy to eat whatever shows up, even if it's just diatoms. I have no idea what the specs are on my little led, but I set it to a similar color as the pictures in the reviews of that grow light. I know 6700K is color temperature, does that relate to visible color? As in, if I match the colors am I getting that color temperature? Or is it more to do with the actual light bulb?

 

Sorry, I couldn't really say that dialing your light in to a similar visible color is achieving the same thing or not. To be honest I don't understand a lot about lighting, but if you want to be sure, smaller plant lights are available pretty cheap on Amazon.

 

Sunlight

 

Sunlight

Will indirect sunlight work? I don't want to put the jar in direct sun because I don't want to cause too much temperature fluctuation (no heater) and I don't have access to a good direct sunlight window anyways.

 

I don't know.....if it can be done direct would be best. Can you get another jar see if it works then swap out as you need. One growing and other is the habitat. Being a 1/2 gallon shouldn't take to long.

 

I don't know.....if it can be done direct would be best. Can you get another jar see if it works then swap out as you need. One growing and other is the habitat. Being a 1/2 gallon shouldn't take to long.

Hmm, I don't have another half gallon but I do have a smaller jar, I could stick that one on the window and if something grows I could use it as a starter for the bigger jar... I wouldn't have an air stone for the small one though

 

You could get a airline splitter. They're really cheap, like 50 cents.

 

You could get a airline splitter. They're really cheap, like 50 cents.

That's a good idea but the issue is I'm a college student living in a dorm and I don't have the window desk I'm sure my roommate would let me put a jar on her desk but I wouldn't want to 8nconvenience her by running an airline across our room! I guess I'll just stick to feeding the larvae spirulina instead of trying to grow algae, for now at least. Thank you!

(I still am curious about the relationship between color temperature and visible color, if anyone has an answer for that).