Phytoplankton keeps dying off

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I've tried a couple of times to start up a phytoplankton culture using a jar of live phytoplankton from algae Barn on one attempt and dinkins on another attempt. Both times my phytoculture is crashed. I'm confused on what I'm doing wrong? I use the Coral ranch f2 fertilizer and I only use two MLs for the 2,000 ml container I'm using. I'm mixing the saltwater properly. I'm not using a heater and I'm using an air stone running very slowly. I also stir the contents everyday. I have attached pictures of what it looked like after I started the culture and what it looks like now.



PXL_20261001_055858620.jpg

PXL_20261006_174416267.MP.jpg
 
Couple of questions!!!
Are you using a single strain or mixed?
Do you have a light source for it?
*Edit, also do you keep the lid cockeyed like that?
 
ahhh looks like there are little lights underneath... not sure if they're grow lights with the proper spectrum....
Based on thoughts...

If its from Algaebarn it's potentially oceanmagik, which is a blend, which the algaes will compete with each other, which IMO would just crash them all

If those aren't grow lights, the spectrum isn't proper for the algae to grow

If that's the air escape...(offset lid) you're probably getting contaminants killing off the algae

So potentially one to all three of those are my guess....
 
Tilted lid is for air escape. Maybe I'll get a better vessel so I can vent properly
 
Tilted lid is for air escape. Maybe I'll get a better vessel so I can vent properly
Try to find a plastic lid, drill one hole for the airline and drill a second smaller hole for air to escape.

For the light, just find a cheap 15 watt light, it doesn't need strong lighting, just needs proper spectrum.
 
Lots of things going on with this. As stated, better light/lid could help, but not necessarily the cause of the crash. Mixed phyto is a very likely cause, and it is best to get strains for culturing.

I typically get mine from Reef Legends since they sell phyto for cultures separately. Lastly, check the salinity of your cultures. Oftentimes you can culture a little lower salinity since it will creep up with evaporation. I almost never culture at 1.025.

There are quite a few guides on culturing, so I would start there. I wouldn't get discouraged, a few key things corrected and culturing your own phyto can be very rewarding.
 
Definitely will be issues with mixed phytoplankton bottle. It'll either crash or if lucky one strain will eventually be left if it doesn't crash.

I second @reef_legend for phytoplankton strains. They sell culture specific strains that are way better than anything else I've used and I've tried a lot of places.

I would also suggest sanitizing the saltwater as well. For easier strains you might be able to get away without sanitizing the SW but long term I think it will eventually crash. I sterilize my fresh SW with pool shock (can use bleach but liquid pool shock doesn't have the fillers), aerate it overnight and then throw in STP pellets to dechlorinate. I tried boiling the SW but didn't have luck.

I have gone over two weeks with a culture doing it this way and I started doing it this way based on Reef Legend's advice and it changed my phytoplantkon culturing big time.

I am slacking and only have 5 strains currently down from 8-9. I do want to add a diatom phytoplankton back into my repertoire and might have to make another purchase from Reef Legends soon!
 
Definitely will be issues with mixed phytoplankton bottle. It'll either crash or if lucky one strain will eventually be left if it doesn't crash.

I second @reef_legend for phytoplankton strains. They sell culture specific strains that are way better than anything else I've used and I've tried a lot of places.

I would also suggest sanitizing the saltwater as well. For easier strains you might be able to get away without sanitizing the SW but long term I think it will eventually crash. I sterilize my fresh SW with pool shock (can use bleach but liquid pool shock doesn't have the fillers), aerate it overnight and then throw in STP pellets to dechlorinate. I tried boiling the SW but didn't have luck.

I have gone over two weeks with a culture doing it this way and I started doing it this way based on Reef Legend's advice and it changed my phytoplantkon culturing big time.

I am slacking and only have 5 strains currently down from 8-9. I do want to add a diatom phytoplankton back into my repertoire and might have to make another purchase from Reef Legends soon!
I've done five at a time, but dang 8-9. Why do you think boiling doesn't work? I've typically done that for Rhodomonas Lens or other sensitive strains. For easy ones like Nanno or Tetra I don't bother, but I also buy refreshers of culture strains every six months or so.
 

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