Guillard's F/2 Formula Microalgae Fertilizer Concentrate — Phytoplankton Culture Media for Reef Tank, Copepods, Rotifers, Brine Shrimp Food | Made in USA | 16.9 fl oz (500ml)

This product really helped my algae take off in growth. I have really dark algae that I feed my corals and copapods.

I originally ordered this product for my nannochlropsis culture in a 1g Poseidon reef systems phyto jars. These jars are sold SPECIFICALLY to grow copepods and different kinds of phyto. I tried adjusting light intensity, amount of bubbles, time the light was on, everything… and still no success. Which is strange because I have had success growing phyto in the past in these very same jars. The only thing I had changed was the fertilizer. I am almost up to 3x the recommended dose in a 1g container and am now to the point where my culture is just crashing. This product is extremely ineffective, and I would not purchase it or recommend t for the purpose of fertilizing phytoplankton cultures.

Also cheap. It doesn't last long though so get a small bottle.

hard to get f2 fertiliser from my country, so i order from amazon. deliver at door with some leakage as shown .advise seller that the product should be pack properly with box since send to oversea . some sediment in the f2 bottle . this the 1st time i learn to culture and it seem this f2 fertiliser work out without any issue for beginner like me(m

I ordered this Coral Ranch F/2 Formula Microalgae Fertilizer Concentrate thats manufactured in the US because, I was told it really brings great life to indoor plants fast and keeps them in great health. I'm new to the whole planting thing. For years I was convinced plants and I didn't work well together, I always did too much or, not enough..... Until I used this!!! Wow, what a difference. The Coral Ranch's F/2 Microalgae Fertilizer is a specially formulated nutrient solution made to use on them to help keep your plants healthy while they grow. I love all the high-quality ingredients, this fertilizer provides the best, and, as im learning, very essential nutrients, vitamins and trace elements. This F/2 Fertilizer is my new favorite choice for my high density phytoplankton cultured plants. This stuff is easy to use and took me a less than a minute to mix. First shake up the F/2. Then, you will want to add about 4ml of this fertilizer with every Gallon of salt water to achieve the best concentration. Be ready to see some optimal results! I highly recommend trying this stuff. This is great stuff when you can find it. This type of fertilizer quality is not easy to come by. Now I know exactly where to go to get this when zi need more. Thank you so much! Keep this fertilizer stored in a cool and dry place away from sunlight. AMAZING STUFF

Product looks like too diluted and doesn't work. It's been two weeks and water is still not green enough, it's looks green because of almost half gallon culture I put in there.

Successful Phytoplankton Cultivation: Growing your own phytoplankton for a reef tank is both cost-effective and rewarding, and The Coral Ranch - Guillard's F/2 Formula Microalgae Fertilizer Concentrate makes it easier. I’ve had nothing but success with this fertilizer, producing six perfect batches so far. Compared to another brand I tried, which resulted in two failed attempts despite proper sanitization and mixing, The Coral Ranch has proven to be far more reliable. Mixing and Usage: I mix two 1-gallon jugs at a time, using a ratio of 1.015 water to 4ml of fertilizer. This straightforward process has consistently yielded excellent results. The lighter color of this fertilizer compared to others doesn’t affect its effectiveness—in fact, it seems to enhance it. Quality and Consistency: The consistency and reliability of The Coral Ranch fertilizer stand out. Each batch has turned out perfect, providing a stable and nutritious food source for my reef. The peace of mind that comes with knowing I can count on this product is invaluable. Better Connection to the Reef: Using this fertilizer not only saves money but also deepens my connection to my reef tank. Cultivating my own phytoplankton adds a personal touch to reef keeping and ensures I know exactly what goes into my tank. Final Thoughts: Overall, The Coral Ranch - Guillard's F/2 Formula Microalgae Fertilizer Concentrate is my go-to choice for growing phytoplankton. It’s reliable, easy to use, and produces consistent results. If you’re looking for a dependable fertilizer to support your reef tank, this one is definitely worth considering.

Been using this every day for a month the usual time for our 5 gallon cultures and we'll after a month still my light passes through it like there is hardly any potency to it highly wish I went with the one my stepfather is using and won't be buying this for bigger cultures again and will stay with smaller ones if I do