Phytoplankton dosing advice

[GiannisK]

About two weeks ago I set up a phytoplankton (Nannochloropsis) culture for my 65g mixed reef. I just got a mandarin and even though it's captive bred I expected it would still be difficult to feed given how tiny they come in. I had some questions regarding phytoplankton culturing/dosing and I know several people here have a lot of experience with this so I'm hoping you have some tips for me.

Some questions I have:

1. I've been getting good growth in roughly a weeklong period, and I've staggered the culture between two cultures in case one crashes. How flexible is the harvesting? My schedule has been very busy lately so I'm wondering how long in your experience I can deviate from harvesting about every week - is 10 days fine, for example? I'm not necessarily saying permanently, just wondering if it's very risky if it happens a few times.
2. What salinity do you culture in? I've been doing about 1.024 but saving more on some salt would be nice.
3. I add about 2 mL of F/2 fertilizer in 32 oz of culture upon harvest. Again, it would be nice to save money in the long term if I can add even less of this - might it just slow the growth or would it limit it entirely? I'm producing a lot more than I can use for my tank so I wouldn't mind slower harvest.
4. I've been dosing about 200 mL once a day per TSA rough guidelines. I wouldn't mind dosing more if it wouldn't cause problems, as again I'm producing a lot more than I can use and the reefing community isn't very big around me for me to give away or sell excess (if you are near New Haven and would like some, however, let me know).
5. Is it helpful to turn off the return pump after dosing so corals can feed on it? I've seen some people say that they will get trapped in filter socks but I wasn't sure if that was nonsense or not.

Thank you!

 

[afboundguy]

1 - I have gone as long as 2 weeks between harvasts and I adjust how dense I make the new cultures as well as amount of fertilizer I put in based on when I think I'll be able to harvest.

2 - I do 1.022 for my sanitized SW give or take a few points. I do it a little low as I assume (think I might have actually tested forever ago) that there will be evaporation in cultures so I do lower salinity to offset this.

3 - I do a total of 2ml per half gallon in all my cultures.

4 - Assuming you mean the Top Shelf Aquatics dosing chart and if so I use the same chart for my dosing.

5 - I don't turn anything off. I had thought about programming the skimmer to shut off but haven't gotten around to it. And I would guess most phyto won't get captured by filter socks. Nanno is 2-5 micron and most roller mats and filter socks only filter out much larger sizes otherwise they would have to be changed out all the time.

 

[GiannisK]

1 - I have gone as long as 2 weeks between harvasts and I adjust how dense I make the new cultures as well as amount of fertilizer I put in based on when I think I'll be able to harvest.

2 - I do 1.022 for my sanitized SW give or take a few points. I do it a little low as I assume (think I might have actually tested forever ago) that there will be evaporation in cultures so I do lower salinity to offset this.

3 - I do a total of 2ml per half gallon in all my cultures.

4 - Assuming you mean the Top Shelf Aquatics dosing chart and if so I use the same chart for my dosing.

5 - I don't turn anything off. I had thought about programming the skimmer to shut off but haven't gotten around to it. And I would guess most phyto won't get captured by filter socks. Nanno is 2-5 micron and most roller mats and filter socks only filter out much larger sizes otherwise they would have to be changed out all the time.

Very helpful thank you!

 

[Kymot]

I have a culture going for 4-5 months now in a 1 gallon plastic container.
I've also gone as long as 2 weeks between harvest and it was fine.
Haven't really been paying too much attention on salinity, just took the fresh saltwater which is at 1.025 (since I do AWC) and add a bit of RODI water to it, so likely lower as well.
I use 2mL of F2 per gallon, and it's been okay, produce really dark phyto
I've been dosing roughly 200mL every other day manually, seems okay. I didn't know the TSA chart, so will look into it. I definitely notice more algae on the glass, maybe it's too much and not consumed that fast.
I also have a copepod culture (tisbee) which I use the phyto for.

 

[GiannisK]

Since the purpose of the dosing of the phytoplankton is to have higher copepod populations in my tank, I wonder if simply dosing will have a significant impact in your opinion? Or do I really need to set up a copepod culture as well to see a difference?

 

[Kymot]

I dose it to my sump too and there’re a bazillion of pods down there. Eitherway, trying to make sure my mandarin wont to hungry and culturing tisbee is super easy as long as u have phyto. I just run 1 gallon of phyto and 1 gallon of pods

 

[afboundguy]

Since the purpose of the dosing of the phytoplankton is to have higher copepod populations in my tank, I wonder if simply dosing will have a significant impact in your opinion? Or do I really need to set up a copepod culture as well to see a difference?

Dosing phyto will give your current pod cultures more food. If you have a refugium/sump you should be more than fine. I do all my pod cultures as I have two mandarins in what is now 70-75 gallons total volume but in a 35 DT. I probably don't need to dose pods as much as I do now that I'm around 70 gallons but at this point I'm just a crazy addicted live food lunatic!

 

[Kymot]

The length one will go for their mandarins hahaha

 

[afboundguy]

The length one will go for their mandarins hahaha

You have no idea lol...