Phytoplankton nutrition

[Randy Holmes-Farley Verified Community Expert]

My question really is what are the main elements / components i need to monitor to keep the green water active without crashes.

I’m not sure which ones get depleted first, but iron and manganese are good candidates.

 

[Subsea]

@Bubba shrimp

Gavin,
Reverse engineer the math of what is being removed by micro algae or macro algae by getting dry algae analysis. Factor in that algae is a sponge and it will absorb heavy metals that are in the water. Note the concentrations
Zn at 139 ppm
Fe at 107 ppm
Mn at 20 ppm
Cu at 7 ppm

Make up water from aquifer showed below detection limit of 0.01 ppm, Instant Ocean was used to bring salinity up to 1.024 SPS.

 

[DxMarinefish]

So its been a case of throwing mud and seeing what sticks as I'm learning everyday. The idea was to try to trickle a flow of water through the anaerobic digester to keep nitrates in tolerance. But the oxegen was too high at 4ppm.
Turning the flow off works to reduce nitrates down to 40ppm then use that water to do water changes as all our saltwater is made diy. The main concern i have is this system doesn't keep the levels low enough in the growout tanks.
With phytoplankton all the system is down to 20ppm while its active. If it crashes the nitrates shoot back up. So my main objective is to co culture zooplankton which the shrimp will utilise for biomass then at harvest I would remove from the system. As with growing superfood seaweed. If I can keep the phytoplankton 365 days I can convert the denitrification tank into breeding or stock tank. So really its only been used as a backup.
All the help and ideas are very much appreciated

I am in the UK.
I culture Tetraselmis, Chlorella Vulgaris and chlorella in 5 Litre Glass Demi-John's. The longest culture I have is Tetraselmis which has been going for 14 months now.
All I do is harvest 80% every 14 days, top up with salt water and add 2 ml of TNC Complete fertiliser every 7 days. I get a very dense culture way better than any of that watery phyto sold in shops.

I have found TNC Complete Plant Fertiliser to be more productive for culturing Phyto based on my experimental comparison with F2. It also worked out cheaper if I buy the 5L bottle.

I do observer strict quarantine procedures. Each culture has its own cleaning kit (brush, sponge, hard line tubes, etc). I wash in lab grade ISOPROPYL ALCOHOL 99.9%.
Fresh salt is mixed over night in a bucket pre-washed with lab grade ISOPROPYL ALCOHOL. I use Instant Ocean (the one sold in individual bags)

I also breed copepods in 4x 110 Litre tubs in my green house and feed them only Photo and powdered Spirulina.

As long as you observe strict processes, your culture should last a very long time.

Nanochloropsis, Tetraselmis and Isocrysis (galbana) are considered the most important algae in culturing zooplankton such as rotifers and ciliates.

Tetraselmis and Dunaliella are motile algae.

Nannochloropsis, nannochloris and chlorella are non motile.

All of the above algae species are normally used to culture rotifers, copepods, artemia, clams, oysters and larval shrimp.

 

[Bubba shrimp]

I am in the UK.
I culture Tetraselmis, Chlorella Vulgaris and chlorella in 5 Litre Glass Demi-John's. The longest culture I have is Tetraselmis which has been going for 14 months now.
All I do is harvest 80% every 14 days, top up with salt water and add 2 ml of TNC Complete fertiliser every 7 days. I get a very dense culture way better than any of that watery phyto sold in shops.

I have found TNC Complete Plant Fertiliser to be more productive for culturing Phyto based on my experimental comparison with F2. It also worked out cheaper if I buy the 5L bottle.

I do observer strict quarantine procedures. Each culture has its own cleaning kit (brush, sponge, hard line tubes, etc). I wash in lab grade ISOPROPYL ALCOHOL 99.9%.
Fresh salt is mixed over night in a bucket pre-washed with lab grade ISOPROPYL ALCOHOL. I use Instant Ocean (the one sold in individual bags)

I also breed copepods in 4x 110 Litre tubs in my green house and feed them only Photo and powdered Spirulina.

As long as you observe strict processes, your culture should last a very long time.

Nanochloropsis, Tetraselmis and Isocrysis (galbana) are considered the most important algae in culturing zooplankton such as rotifers and ciliates.

Tetraselmis and Dunaliella are motile algae.

Nannochloropsis, nannochloris and chlorella are non motile.

All of the above algae species are normally used to culture rotifers, copepods, artemia, clams, oysters and larval shrimp.

All this information is wonderful
I'm reluctant to add fertilizer as the volume of water we have in 1 system is 50,000 ltrs and its the nutrients im trying to reduce. Adding fertilizer would increase phosphorus wouldn't it? Already above 10ppm

 

[Dennis Cartier]

All this information is wonderful
I'm reluctant to add fertilizer as the volume of water we have in 1 system is 50,000 ltrs and its the nutrients im trying to reduce. Adding fertilizer would increase phosphorus wouldn't it? Already above 10ppm

I was curious about the TNC Complete Plant Fertilizer so I googled them. They appear to have a TNC Complete Lite, which lacks N and P. Perhaps test that on a sample of your water column to see if it allows phyto to reproduce and also do an ICP on the dosed sample to check on traces and heavy metals as it relates to shrimp. Though the product says it is safe for shrimp and other inverts. Just an idea.

 

[Bubba shrimp]

I was curious about the TNC Complete Plant Fertilizer so I googled them. They appear to have a TNC Complete Lite, which lacks N and P. Perhaps test that on a sample of your water column to see if it allows phyto to reproduce and also do an ICP on the dosed sample to check on traces and heavy metals as it relates to shrimp. Just an idea.

I currently have a few test running which I will icp test and post here. I have production tanks running with 80ppm nitrate. Offline production tank with phytoplankton 20ppm nitrate. And one glass 20 ltr tank in a polytunnel with 0,0,0 ammonia,nitrite,nitrates with yellow phytoplankton. Should be able to compare whats been depleted and workout a dossing routine.

 

[DxMarinefish]

All this information is wonderful
I'm reluctant to add fertilizer as the volume of water we have in 1 system is 50,000 ltrs and its the nutrients im trying to reduce. Adding fertilizer would increase phosphorus wouldn't it? Already above 10ppm

Have you considered running a few dedicated tubs as algae refugiums, or even Algae turf Scrubbers (ATS)?

You could design one refugium to service a few of your tubs. Won't need much artificial lighting (depending on your farm housing). It would serve as a passive nutrient export/controller.

ATS can be powerful, but will need lights and thus add to operational cost.

But if either can reduce mortality, increase productivity and growth rate then your ROI might be positive.

 

[DxMarinefish]

 

[Bubba shrimp]

Have you considered running a few dedicated tubs as algae refugiums, or even Algae turf Scrubbers (ATS)?

You could design one refugium to service a few of your tubs. Won't need much artificial lighting (depending on your farm housing). It would serve as a passive nutrient export/controller.

ATS can be powerful, but will need lights and thus add to operational cost.

But if either can reduce mortality, increase productivity and growth rate then your ROI might be positive.

Yes experiment with growing algae like cleto and sea lettuce in a refugium, but our water is more like bio flock and they got covered in dusty settlement. Phytoplankton is definitely they way for us to have rotifers and copods for the shrimp to eat.