help with phyto culture

[tableforglasses]

I’ve read in many places that culturing phytoplankton is fairly easy, but for some reason I’m really struggling with it.

To keep things simple, I purchased the PhytoTank from Poseidon Reef. Here is my current process:

• Fresh RODI water mixed to the correct salinity
• Water produced with an Aquatic Life RODI system
• Sediment, carbon, and DI filters were recently replaced
• All equipment cleaned with alcohol and allowed plenty of time to dry and dissipate
• Lights running 18 hours on and 6 hours off
• Culture started with 250 mL of live phytoplankton from Dinkins
• Added 2 mL each of Fertilizer A and Fertilizer B

My first culture lasted less than a week before it began losing color. With my second attempt, the culture started getting noticeably lighter the day after setup and was almost clear by the end of day two.

I can’t figure out what I might be doing wrong. Does anything about my setup or process stand out? Are there any other factors I should check or changes you would recommend?

 

[pooootiqe]

Try starting with a pure culture instead of a mixed one. @Reef By Steele has a lot of strains to choose from.

The starting amount also seems high. I do 1:100 but others might go higher.

At which day do you see the deepest green from the culture?

 

[EnterName]

I assume you have simply followed Poseidon Reef's instructions?
https://cdn.shopify.com/s/files/1/0759/4967/0552/files/Phyto_Setup_Guide.pdf?v=1774125968

250mL for a first start in 3.5L containers sounds fine to me. I don't know what fertilizer they are using but I would assume it's F/2 or similar. Maybe it's just a bad batch... I would buy an actual F/2 fertilizer if you can get your hands on it and then use 1mL per L of culture. It's best if the fertilizer is split into 2 or better 3 separate bottles.

You can check out my tutorial on how to culture phytoplankton: https://www.reef2reef.com/threads/another-phytoplankton-culture-tutorial.1165682/ It might contain some information you find useful.

 

[tableforglasses]

I assume you have simply followed Poseidon Reef's instructions?
https://cdn.shopify.com/s/files/1/0759/4967/0552/files/Phyto_Setup_Guide.pdf?v=1774125968

250mL for a first start in 3.5L containers sounds fine to me. I don't know what fertilizer they are using but I would assume it's F/2 or similar. Maybe it's just a bad batch... I would buy an actual F/2 fertilizer if you can get your hands on it and then use 1mL per L of culture. It's best if the fertilizer is split into 2 or better 3 separate bottles.

You can check out my tutorial on how to culture phytoplankton: https://www.reef2reef.com/threads/another-phytoplankton-culture-tutorial.1165682/ It might contain some information you find useful.

thanks for the tutorial. Yep, I followed their instructions. Is it possible that their recommended 2 ml of each fertilizer is too little?

 

[EnterName]

thanks for the tutorial. Yep, I followed their instructions. Is it possible that their recommended 2 ml of each fertilizer is too little?

If they actually use F/2 it would be "low" but sufficient as you start with 250mL culture already. You can try with more, but I doubt that's the reason. Maybe you don't move the water enough/don't push enough air through so everything stays in movement? If the cells collect at the bottom they won't survive.

 

[tableforglasses]

here is what my water flow looks like

 

[EnterName]

here is what my water flow looks like

[...]

Hard to tell, to be honest. If you feel like something is gathering on the bottom instead of staying in suspension you will have to crank it up.

 

[pooootiqe]

Nanno doesn’t need much to be suspended, diatoms that I’ve played with need a lot more. From the video looks like you could turn up the airflow, tho.

 

[tableforglasses]

I have a hygger pump and it's maxed out on airflow. Shouldn't this be enough?

Maximum air flow: 70 GPH; Power: 4.5W. 50~70gallon fish tank is suitable.

 

[tableforglasses]

Does it matter that the Dinkins is a 6 species blend? Their chaeto is awesome so i used them for phyto too. I saw the recommendation for Reef by Steele. Are there any other brands you have had great success with as a starter culture?

 

[EnterName]

Does it matter that the Dinkins is a 6 species blend? Their chaeto is awesome so i used them for phyto too. I saw the recommendation for Reef by Steele. Are there any other brands you have had great success with as a starter culture?

Cultures are usually kept as sterile as possible (and one specific species). I'm not sure it applies to the 6 species in the blend, but many algae produce substances to inhibit the growth of other algae so this is a thing to consider.
These blends are certainly not meant as culture starter so they might contain many dead cells and contaminants, maybe even small critters that eat the micro algae and are therefore actually harmful to the culture's density.

I recommend using actual starter cultures that are as clean as possible. In my previously linked tutorial thread, I even have a section dedicated to the analysis of the culture's purity using a microscope.

 

[tableforglasses]

Thanks for the reply, I read that section in your thread and maybe i need to invest in a microscope to do some real study. I know that cleaning the containers is very important and it sounded like from that thread you put a lot of work into that but is any of that alleviated by the fact that the Poseidon System uses a fresh bag each time a culture is started or is split and it never actually touches the glass?

 

[EnterName]

Thanks for the reply, I read that section in your thread and maybe i need to invest in a microscope to do some real study.

As you may have already seen, I'm really into microscopy, but I wouldn't invest in a microscope if it were just for some Nannochloropsis cultures, which are quite easy to keep. For more delicate cultures it might be useful, and it can certainly help to identify issues in your tank, as well as being a very fun thing to do anyway, but don't waste money if you just want to check on a bit of phytoplankton.

I know that cleaning the containers is very important and it sounded like from that thread you put a lot of work into that but is any of that alleviated by the fact that the Poseidon System uses a fresh bag each time a culture is started or is split and it never actually touches the glass?

Using bags will let you avoid cleaning the glass, but it makes actual sterilization impossible because the bags aren't heat resistant. You may be able to use a bleach disinfection approach to treat the water, which would help with the long-term success of your culture(s).

The thing is, if your approach isn't "clean" enough, every new batch might introduce more and more "impurities" (organisms that compete with the phytoplankton over nutrients or even worse actively prey on the phytoplankton cells). To maximize phytoplankton density and reduce the risk of any contamination with other organisms, I personally try to absolutely sterilize the used water (especially for more delicate cultures). This allows me to get lazy with harvesting and start cultures from just a few cells without too much trouble. Sometimes you can even recover pretty much crashed cultures this way, so I really like the presented approach.

For the beginning it might be enough to go with the bags, but I can't promise you that you'll be able to keep cultures alive and start culture after culture over weeks or months without buying a new starter culture from time to time or seeing a decline in culture density.

I don't know if the tubing is changed every batch as well, but if not, you will certainly have to clean the air-line that is submerged in your culture, or you will introduce algae that attaches to the tube and is therefore not actual plankton (plankton is per definition freely floating).

 

[tableforglasses]

Thanks for the dialogue! So do you think it would be better to eliminate the bags and focus on cleaning the containers better without the bags? I might have to go the bleach route since the lights are around the container outside and wrapped in rubber.

 

[EnterName]

Thanks for the dialogue! So do you think it would be better to eliminate the bags and focus on cleaning the containers better without the bags? I might have to go the bleach route since the lights are around the container outside and wrapped in rubber.

I think you can go with the bags for now. But if your cultures don't work long term I would change the overall approach. For now you need to get a single batch running and find out what's the issue. I don't think the bags or impurities are already the issue

 

[pooootiqe]

Does it matter that the Dinkins is a 6 species blend? Their chaeto is awesome so i used them for phyto too. I saw the recommendation for Reef by Steele. Are there any other brands you have had great success with as a starter culture?

Reef legends, Carolina (likely mixed culture - be warned!), random eBay sources for nannochlorpsis and tetraselmis; check the live stock selling subforum as well.