DIY phytoplankton Culturing

I have been thinking of culturing my own phyto for a while now.. recently my local store stopped selling some fresh cultures so i decided to try out my own.

Ideally one would start with a specific strain however there was slim pickens where i live so i decided to go with the only live culture i could find. I found a nice big bottle of phytofeast to get started.
I mixed the salt water to around 1.019 – 1.020. For the fertalizer I decided to use miraclegrow for the first batch (and ordered some F2 for future cultures).

I mixed two different batches.  The 2L bottle was my first attempt with 5ml of miracle grow.  The second batch I added 1ml of miraclge grow to the 500ml bottle and  thew the bottle into the microwave for 2 min to sterilize it.. once it cooled i added some live phyto (mixed much darker than the first one) and added it to the shelf

The light is currently on a timer for to run at 16 hours per day…

Day1:  will see how it goes! 🙂



  • I cultured phytoplankton from Phyto Feast a while back successfully. I used a gallon jug with 1.019 salinity and 5 ml of miracle grow under a 6500k light. I had it growing for a long time until I got lazy and didn’t keep the bottles fresh. Once producing phytoplankton you have to culture every couple weeks otherwise it will suffocate itself. Good luck with this, I hope it’s going well for you.

    • Thanks Eric! So far so good. I ended up getting proper phyto fertilizers (and I admin i dont harvest enough) as i’m currently making way more than i need.. My filter feeders are happy campers !

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