Measuring Salinity of Phytoplankton Culture

[ThePurple12]

I know refractometers use light to get a salinity reading, so wouldn't the tint from phytoplankton influence this? Would a hydrometer be influenced too, because of the phyto cells in the water?

 

[ThePurple12]

I guess the best way would be to dilute the culture water with fresh water, say 1:10, then multiply the reading by 10? It wouldn't be the most accurate, but it should be close enough.

 

[ThePurple12]

Well, I just answered my own question. I measured the salinity of greenwater with and without diluting, and the result was the same, so it looks like phyto in the water doesn't affect the reading- at least not significantly.

 

[SaltBabies]

Well, I just answered my own question. I measured the salinity of greenwater with and without diluting, and the result was the same, so it looks like phyto in the water doesn't affect the reading- at least not significantly.

Great job. I've always wondered but never worried about it.
Now you've answered that question.

What kind of phyto are you growing?

 

[ThePurple12]

Great job. I've always wondered but never worried about it.
Now you've answered that question.

What kind of phyto are you growing?

Glad to help!

It’s just Nannochloropsis. I tried Iso, but couldn’t get it to grow.

 

[SaltBabies]

Glad to help!

It’s just Nannochloropsis. I tried Iso, but couldn’t get it to grow.

yeah Iso is tricky and my nanno keeps invading it. I read somewhere it actually grows better if you co-grow brine with it. I know it likes to grow in my seahorse grow out tank. which is drilled so it has good flow and steady nutrients.

when I grow it in bottles it's a bust

 

[ThePurple12]

Good to know. If I ever succeed with bluestripe pipes I’ll try some Iso in the grow out tank.

 

[ThRoewer]

The algae cells do not affect the refraction gradient of saltwater, so no, the algae do not affect the readings of a refractometer.

 

[taricha]

The algae cells do not affect the refraction gradient of saltwater, so no, the algae do not affect the readings of a refractometer.

nor do the neutrally buoyant algae cells change the density of the water, so a swing arm works fine too.

 

[ThePurple12]

Thanks for the confirmation guys.

 

[ThRoewer]

yeah Iso is tricky and my nanno keeps invading it. I read somewhere it actually grows better if you co-grow brine with it. I know it likes to grow in my seahorse grow out tank. which is drilled so it has good flow and steady nutrients.

when I grow it in bottles it's a bust

Iso and T-Iso need extreme diligence in sterilization of culture water and equipment. Any sloppiness there and you will get contaminations.