Lighting Period For Brewing Phytoplankton?

PeterC99 · May 2, 2022

Curious as to the optimal lighting period for growing phytoplankton? Does anyone leave their light on 24/7? What lighting period has given you the optimal yield?

Thank You!

gbroadbridge · May 2, 2022

PeterC99 said:
Curious as to the optimal lighting period for growing phytoplankton? Does anyone leave their light on 24/7? What lighting period has given you the optimal yield?

Thank You!

I'v used 16 hours on 8 hours full darkness which works for me as described in this article

Culture your own Phytoplankton | Melev's Reef

www.melevsreef.com

dthom · May 2, 2022

Same here. Some darkness each day seems to be best

Spare time · May 2, 2022

I turn it off when I wake up and off when I sleep

PeterC99 · May 2, 2022

dthom said:
Same here. Some darkness each day seems to be best

Wondering if a shorter darkness period (maybe 4 hours) would yield more phytoplankton?

ReefChasers · May 2, 2022

16 hours seems to work perfect for us.

ReefChasers · May 2, 2022

PeterC99 said:
Wondering if a shorter darkness period (maybe 4 hours) would yield more phytoplankton?

No, recently helped my high school student son do a phytoplankton science project for school where we tested different photo periods (16, 20, and 12). 16 performed the best, 12 the worst, but it seemed stunted at 20. We ran a few harvest over the course of 3-4 weeks before we compiled it all on a board for with photos etc and a report for his school project.

It was a lot of fun

ReefChasers · May 2, 2022

Sorry, what we tested at 13 hours, 16 hours and 19 hours.

PeterC99 · May 2, 2022

ReefChasers said:
Sorry, what we tested at 13 hours, 16 hours and 19 hours.

Hope your son got a TOP grade! Obviously destined to be one of America’s next great scientist!!!

Excellent work!

gbroadbridge · May 2, 2022

PeterC99 said:
Wondering if a shorter darkness period (maybe 4 hours) would yield more phytoplankton?

It normally grows faster than you can use it

ReefChasers · May 2, 2022

gbroadbridge said:
It normally grows faster than you can use it

I tend to have the opposite problem if you figure you are harvesting at home for personal use and only doing 1 gallon batches that means your weekly harvest is only around 1800ml. My 150 gallon at-home-reef gobbles up the 1800ml a week and loves every minute of it. I mean that's dosing wayyyyy more than what the sellers of phytoplankton typically recommend (because if you dose this much you'd have to go broke trying to buy it

) but I find it's the absolute best form of food I can feed so I tend to do so very heavily especially since it's free when harvesting at-home.

At work we harvest in 5 gallon batches about 4 of them going at once so we get nice weekly yields, still we dump about a 1/2 gallon every other day into each of our systems (3x a week) but these are 1200 gal systems. Best food is free food and hey live phytoplankton, you can't go wrong with that!

If anyone is interested in a 5 gallon DIY reactor let me know.... there are some options! lol

ReefChasers · May 2, 2022

PeterC99 said:
Hope your son got a TOP grade! Obviously destined to be one of America’s next great scientist!!!

Excellent work!

He did get first place! I let him take the poisedon harvest system in school for project day so he got to plug it in and I'm sure all the kids were Oooooh Ahhhh at the Mtn Dew Color lol

PeterC99 · May 2, 2022

ReefChasers said:
He did get first place! I let him take the poisedon harvest system in school for project day so he got to plug it in and I'm sure all the kids were Oooooh Ahhhh at the Mtn Dew Color lol

Congrats to your son!

Maybe your sons school will let him build an amazing reef at school. What a great way to get the next generation of reefers started.

alberto1999 · May 4, 2022

How about the best light spectrum?

Hallowhead · May 4, 2022

I keep struggling to maintain my second batch. First batch comes out great I harvest and than second batch crashes (turns yellow) before dark green. I'm wondering if it was the type of light as I was using 16 hour periods

JGT · May 4, 2022

I follow the 16 hours on/ 8 hours off schedule and use just a plain 60 W bulb. Phyto as far as the eye can see.

ReefChasers · May 5, 2022

Hallowhead said:
I keep struggling to maintain my second batch. First batch comes out great I harvest and than second batch crashes (turns yellow) before dark green. I'm wondering if it was the type of light as I was using 16 hour periods

First week color is always lighter. I find when yellow its struggling to start then sometimes skip harvest and add more fert. This usually kicks it up and fixes the problem. I use f2 fert and always dose the max instead of the min (recommend 1.5ml but I dose 3ml all the time) thats for a single gallon batch.

Also i try not to take more than half each harvest I find leaving behind a solid half keeps it rolling much better.

I tend to wait 1 week in between harvests and not longer. The longer you wait the more risk you run of a crash. 1 week intervals yields plenty dense phyto very dark green.

In fact, once a batch is really rolling good you can sometimes harvest even faster than 7 days but I always just judge by the color.

My current batch has been rolling for at least 3 months so this method seems to work well enough.

DaJMasta · May 5, 2022

I had been using an 18 hour photoperiod with 6 hours of dark, but when I had some trouble with crashing isochrysis (ended up being mold on the air pump's input filter), I swapped over to always on to try to grow in replacement cultures faster. Using the 18 hour photoperiod I was harvesting every 6 days and resetting the culture with fresh saltwater, fertilizer, and about 1/6th of the previous culture, but with a 24 hour photoperiod I can achieve the same density in 5 days with the same setup. Only problem is the always on light at night, so provided my usage stays low enough to allow the 6 day cycle (a bunch of copepod cultures and limited rack space in front of the lights to grow), I'll probably go back to the 18h photoperiod so I can use less saltwater and have some real darkness in the room.

Microcosm Reefer · May 5, 2022

Have a culture of Nanno going on 3 months now of 24/7 lighting. No complaints so far. Harvest around the 7 day mark. So much left over not really concerned about optimal cell count.

Hallowhead · May 5, 2022

ReefChasers said:
First week color is always lighter. I find when yellow its struggling to start then sometimes skip harvest and add more fert. This usually kicks it up and fixes the problem. I use f2 fert and always dose the max instead of the min (recommend 1.5ml but I dose 3ml all the time) thats for a single gallon batch.

Also i try not to take more than half each harvest I find leaving behind a solid half keeps it rolling much better.

I tend to wait 1 week in between harvests and not longer. The longer you wait the more risk you run of a crash. 1 week intervals yields plenty dense phyto very dark green.

In fact, once a batch is really rolling good you can sometimes harvest even faster than 7 days but I always just judge by the color.

My current batch has been rolling for at least 3 months so this method seems to work well enough.

So when you harvest you're using the same container or sterilizing before adding f/2?

I've been rolling right into my second batch in the same unsterilized container.

It gets a crusty yellow, it starts greenish and than goes crusty yellow which I than know it crashes. I just don't get it